JP6237641B2 - Membrane switch and article using the same - Google Patents

Description

  The present invention relates to a membrane switch, which is a sheet-like switch, and its use.

  The membrane switch is provided with conductor parts (parts made of conductive material that serves as contact points for the switches) on each of the two substrates so that the conductor parts face each other and a gap is secured between the conductor parts. This is a sheet-like switch in which substrates are stacked with a spacer interposed (Patent Document 1).

FIG. 10 is a cross-sectional view schematically showing the structure of an enlarged one switch portion of a conventional membrane switch. As shown in the figure, conductor portions 110 and 210 serving as contact points are formed on two substrates 100 and 200, respectively, and a spacer 300 is provided so that the conductor portions 110 and 210 face each other with a predetermined interval s. Is intervening.
In the embodiment of FIG. 10A, the area of the conductor portions 110 and 210 is larger than the opening area of the through-hole 310 provided in the spacer 300, so that the outer peripheral edges of the conductor portions 110 and 210 are the through-holes of the spacer. It protrudes from the opening. In FIG. 10A, the conductor portion is drawn thick for the sake of explanation. However, the conductor portion is actually thin, and the spacer is not greatly compressed by the conductor portion during assembly. On the other hand, in the embodiment of FIG. 10B, the area of the conductor portions 110 and 210 is smaller than the opening area of the through hole 310 provided in the spacer 300, and the conductor portions 110 and 210 are accommodated in the through hole of the spacer. Facing each other.

  At least one of the opposing conductor portions 110 and 210 in the membrane switch is movable (can be displaced, contacted and returned to the other conductor portion) by the elasticity of the substrate. Therefore, as shown by the thick arrows in FIG. 10, when the movable conductor side substrate is pressed from the outside, the two conductor portions 110 and 210 come into contact with each other, and when the pressure is released, the contact is released and turned on and off. Can be obtained.

  Membrane switches have a simple structure and can be manufactured at low cost, and they have high reliability of on / off operation, so they can be used in a wide range of fields, such as mobile phone and personal computer keyboards, home appliance switches, and remote controller switches. Many are used.

  The present inventors have studied in detail the structure and function of the conventional membrane switch as described above, and focus on the fact that the conventional membrane switch can simply obtain on (closed) and off (open) signals. did. And according to the magnitude of the pressure applied from the outside, not only on and off, but a new structure capable of outputting a signal according to the magnitude of the pressure applied from the outside is given to the membrane switch, It was taken up as a problem that the use should be expanded more.

Japanese Patent Application Laid-Open No. 01-076665

  An object of the present invention is to provide a membrane switch having a new structure capable of obtaining a signal corresponding to the magnitude of pressure applied from the outside, and its application.

  As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention have, as a result of the conventional membrane switch structure, an organic material exhibiting piezoelectricity in the gap between the contacts facing each other with a predetermined gap. It is found that a signal corresponding to the pressure applied from the outside can be obtained by arranging (which may be filled or having a void), and the present invention has been completed.

（式中、ｋは１または２の整数、Ｒ^１はＣ_１〜Ｃ_８の置換もしくは非置換のアルキル基、または、ハロゲン原子、アルコキシ基もしくはニトロ基で置換されていてもよいベンジル基を表す。）
式（ＩＩ）：

（式中、ｋは１または２の整数、Ｒ^２はＣ_３〜Ｃ_１６非置換アルキル基、または、水素原子の一部もしくは全部がハロゲン原子、Ｃ_３〜Ｃ_１２脂環式炭化水素基、Ｃ_１〜Ｃ_６アルコキシ基、シアノ基、置換基を有していてもよいフェニル基、置換基を有していてもよいフェニルアルコキシ基もしくは置換基を有していてもよいフェニルアルキルカルバメート基で置換されたＣ_１〜Ｃ_６アルキル基を表す。但し、Ｒ^２は式（Ｉ）のＲ^１と同一の基となることはない。）
式（ＩＩＩ）：

（式中、Ｒ^３はメチル基、ベンジル基または−（ＣＨ_２）_４−ＮＨＸ基（但し、Ｘはハロゲン原子もしくはＣ_１〜Ｃ_６アルコキシ基で置換されていてもよいベンジルオキシカルボニル基、ハロゲン原子で置換されていてもよいＣ_１〜Ｃ_６アルキルカルボニル基、アリルオキシカルボニル基、フルオレニルアルコキシカルボニル基、Ｃ_１〜Ｃ_６アルキル基もしくはニトロ基で置換されてもよいベンゼンスルホニル基、またはＣ_１〜Ｃ_６アルキルオキシカルボニル基を表す。）を表す。）
式（ＩＶ）：

（式中、ｋは１または２の整数、Ｒ^４はＣ_１〜Ｃ_１２アルコキシ基、水素原子の一部もしくは全部がハロゲン原子で置換されたＣ_１〜Ｃ_１２アルキル基、または、Ｃ_１〜Ｃ_１２アルキルカルボニル基を表し、ｍ個のＲ^４は同一でも異なってもよい。ｌは６〜１２の整数、ｍは１〜３の整数を表す。）
式（Ｖ）：

（式中、Ｒ^５は、水素原子、メチル基、−ＣＨ（ＯＨ）ＣＨ_３、Ｃ_３〜Ｃ_４分岐鎖状アルキル基、または、―（ＣＨ_２）_ｎ−Ｚ（但し、ｎは１〜４の整数、Ｚはヒドロキシ基、メルカプト基、カルボキシ基、メチルスルファニル基、アミノ基、置換アリール基、アミノカルボニル基、−ＮＨ-Ｃ（ＮＨ₂）=ＮＨ、

、または

を表す。）を表す。）
［１１］ ポリα−アミノ酸が、
（Ａ）式（Ｉ）で表される１種以上の単位と、
（Ｂ）式（ＩＩ）で表される単位、式（ＩＩＩ）で表される単位および式（ＩＶ）で表される単位から選択される１種以上の単位と
を含有するポリα−アミノ酸である、上記［１０］記載のメンブレンスイッチ。
［１２］ Ｒ^２がＣ_６〜Ｃ_１６非置換アルキル基、または、水素原子の一部もしくは全部がフッ素原子もしくはノルボルニル基で置換されたＣ_１〜Ｃ_６置換アルキル基である、上記［１０］または［１１］記載のメンブレンスイッチ。
［１３］ Ｒ^２がｎ−ヘキシル基、ｎ−ドデシル基、２−ノルボニルメチル基または２，２，２−トリフルオロエチル基である、上記［１０］または［１１］記載のメンブレンスイッチ。
［１４］ Ｒ^３がメチル基または−（ＣＨ_２）_４−ＮＨＸ基（但し、Ｘはベンジルオキシカルボニル基を表す）である、上記［１０］〜［１３］のいずれか一つに記載のメンブレンスイッチ。
［１５］ Ｒ^４がＣ_１〜Ｃ_６アルコキシ基、水素原子の一部もしくは全部がフッ素原子で置換されたＣ_１〜Ｃ_１２アルキル基、または、Ｃ_３〜Ｃ_９アルキルカルボニル基である、上記［１０］〜［１４］のいずれか一つに記載のメンブレンスイッチ。
［１６］ Ｒ^４がメトキシ基、ブトキシ基、ヘキシルオキシ基、トリフルオロメチル基、またはｎ−ヘキシルカルボニル基である、上記［１０］〜［１４］のいずれか一つに記載のメンブレンスイッチ。
［１７］ Ｒ^５が水素原子、４−アミノブチル基、４−ヒドロキシベンジル基、アミノカルボニルエチル基、または−（ＣＨ_２）_３−ＮＨ-Ｃ（ＮＨ₂）=ＮＨである、上記［１０］〜［１６］のいずれか一つに記載のメンブレンスイッチ。
［１８］ ポリアミノ酸が、グルタミン酸、アスパラギン酸、リジンならびにその誘導体から選択される１種または２種以上の単位を含有するポリα−アミノ酸である、上記［１０］記載のメンブレンスイッチ。
［１９］ ポリアミノ酸が、グルタミン酸メチルエステル、グルタミン酸ベンジルエステル、アスパラギン酸ベンジルエステル、Nε-カルボベンゾキシ-Ｌ-リジンから選択される１種または２種以上の単位を含有するポリα−アミノ酸である、上記［１０］記載のメンブレンスイッチ。
［２０］ ポリα−アミノ酸が、γ−メチル−Ｌ−グルタミン酸／γ−ヘキシル−Ｌ−グルタミン酸共重合体、γ−メチル−Ｌ−グルタミン酸／γ−ドデシル−Ｌ−グルタミン酸共重合体、γ−ベンジル−Ｌ−グルタミン酸／γ−ドデシル−Ｌ−グルタミン酸共重合体、γ−メチル−Ｌ−グルタミン酸／γ−２，２，２−トリフルオロエチル−Ｌ−グルタミン酸共重合体、γ−メチル−Ｌ−グルタミン酸／γ−２−ノルボルニルメチル−Ｌ−グルタミン酸共重合体、γ−ベンジル−Ｌ−グルタミン酸／γ−２−ノルボルニルメチル−Ｌ−グルタミン酸共重合体、γ−メチル−Ｌ−グルタミン酸／γ−（６−（ｐ−メトキシフェノキシ）−１−ヘキシル）−Ｌ−グルタミン酸共重合体、γ−メチル−Ｌ−グルタミン酸／γ−（６−（ｐ−ヘキシルカルボニルフェノキシ）−１−ヘキシル）−Ｌ−グルタミン酸共重合体、γ−メチル−Ｌ−グルタミン酸／γ−（１０−（ｐ−メトキシフェノキシ）−１−デシル）−Ｌ−グルタミン酸共重合体、γ−メチル−Ｌ−グルタミン酸／γ−（６−（ｐ−ブトキシフェノキシ）−１−ヘキシル）−Ｌ−グルタミン酸共重合体、γ−メチル−Ｌ−グルタミン酸／γ−（６−（ｐ−ヘキシルオキシフェノキシ）−１−ヘキシル）−Ｌ−グルタミン酸共重合体、γ−メチル−Ｌ−グルタミン酸／γ−（６−（３，５−ビス（トリフルオロメチル）フェノキシ）−１−ヘキシル）−Ｌ−グルタミン酸共重合体、γ−メチル−Ｌ−グルタミン酸／Ｎ^ε−ベンジルオキシカルボニル−Ｌ−リジン共重合体、γ−ベンジル−Ｌ−グルタミン酸／Ｎ^ε−ベンジルオキシカルボニル−Ｌ−リジン共重合体、γ−メチル−Ｌ−グルタミン酸／Ｌ−フェニルアラニン共重合体、γ−ベンジル−Ｌ−グルタミン酸／Ｌ−フェニルアラニン共重合体、およびγ−ベンジル−Ｌ−グルタミン酸／Ｌ−アラニン共重合体から選択される１種以上である、上記［１０］記載のメンブレンスイッチ。
［２１］ ポリα−アミノ酸がランダム共重合体である、上記［１１］〜［２０］のいずれか一つに記載のメンブレンスイッチ。
［２２］ ポリα−アミノ酸がブロック共重合体である、上記［１１］〜［２０］のいずれか一つに記載のメンブレンスイッチ。
［２３］ ポリα−アミノ酸の重量平均分子量（Ｍｗ）が１，０００〜５，０００，０００であることを特徴とする、上記［１０］〜［２２］のいずれか一つに記載のメンブレンスイッチ。
［２４］ 導体部同士の間の隙間に充填または空隙が存在するように配置されている有機材料に対し、該導体部同士の間での電圧印加による分極処理が施された、上記［１］〜［２３］のいずれか一つに記載のメンブレンスイッチ。
［２５］ 第１の基板および第２の基板のいずれか一方または両方が、可とう性を有する材料によって形成されたフレキシブル基板である、上記［１］〜［２４］のいずれか一つに記載のメンブレンスイッチ。
［２６］ 第１の基板、第２の基板、および、スペーサーが可とう性を有する材料によって形成されたものであり、当該メンブレンスイッチ全体が可とう性を有するものである、上記［１］〜［２４］のいずれか一つに記載のメンブレンスイッチ。
［２７］ 第１の基板とスペーサーとの間、および、第２の基板とスペーサーとの間の、いずれか一方または両方に、接着剤層が介在している、上記［１］〜［２４］のいずれか一つに記載のメンブレンスイッチ。
［２８］ 導体部同士の間の隙間に充填または空隙が存在するように配置されている有機材料と、該導体部との間に、接着剤層が介在している、上記［１］〜［２７］のいずれか一つに記載のメンブレンスイッチ。
［２９］ 第１の導体部、第２の導体部、および、それら導体部に接続された配線回路が、第１、第２の基板面に対する印刷によって形成されたものである、上記［１］〜［２８］のいずれか一つに記載のメンブレンスイッチ。
［３０］ 上記［１］〜［２９］のいずれか一つに記載のメンブレンスイッチが、圧力を受ける物品の表層に沿って配置され、それによって、受ける圧力に応じた信号を発する機能が付与されている、前記物品。That is, the present invention provides the following.
[1] The first conductor portion is provided on the first substrate, the second conductor portion is provided on the second substrate, and the conductor portions are opposed to each other with a gap therebetween. The substrate and the second substrate are laminated via a spacer,
The gap is filled with an organic material exhibiting piezoelectricity, or
In the gap, an organic material exhibiting piezoelectricity is disposed such that a gap exists between the organic material and one conductor portion.
Membrane switch.
[2] A plurality of first conductor portions are provided in a predetermined arrangement pattern on the first substrate, and a plurality of second conductor portions are provided in an arrangement pattern corresponding to the arrangement pattern on the second substrate. ,
The first substrate and the second substrate are laminated via a spacer so that the plurality of conductor portions face each other with a gap and a plurality of conductor portion pairs are arranged, The membrane switch according to the above [1], wherein the gap between the conductor portions of the conductor portion pair is filled with an organic material exhibiting piezoelectricity or disposed so that a gap exists.
[3] The membrane switch according to [1] or [2], wherein a gap between the conductor portions is surrounded by a spacer.
[4] The device according to any one of [1] to [3], wherein the spacer is formed by punching a film having a thickness of the spacer and made of a material of the spacer. Membrane switch.
[5] The above [1] to [1], wherein the spacer is formed by applying an insulating material to one or both of the main surface of the first substrate and the main surface of the second substrate. The membrane switch according to any one of [3].
[6] The membrane switch according to [5] above, wherein the material of one or both of the first substrate and the second substrate and the material of the spacer are the same insulating material.
[7] An organic material exhibiting piezoelectricity is
(A) an organic piezoelectric body having piezoelectricity itself,
(B) By using an organic piezoelectric body having piezoelectricity as a base material, and fillers made of other materials having the piezoelectricity itself dispersed therein, the piezoelectricity of the base material itself is different as a whole. Composite materials that are organic materials that exhibit piezoelectricity, or
(C) An organic material having no piezoelectricity is used as a base material, and a filler made of a material having piezoelectricity is dispersed therein, so that it is selected from composite materials that are organic materials that exhibit piezoelectricity as a whole. The membrane switch according to any one of [1] to [6], which is one or more types.
[8] The membrane switch according to any one of [1] to [6], wherein the organic material exhibiting piezoelectricity is a polyamino acid.
[9] The polyamino acid is glycine, alanine, valine, leucine, isoleucine, arginine, asparagine, aspartic acid, cystine, cysteine, glutamine, glutamic acid, histidine, lysine, ornithine, serine, threonine, tryptophan, methionine, phenylalanine, tyrosine and The membrane switch according to [8] above, which is a poly α-amino acid containing one or more units selected from the derivatives.
[10] The polyamino acid is
A unit represented by the following formula (I):
A unit represented by the following formula (II):
A unit represented by the following formula (III):
[8] The poly [alpha] -amino acid containing a unit represented by the following formula (IV) and one or more units selected from the unit represented by the following formula (V) The described membrane switch.
Formula (I):

(In the formula, k represents an integer of 1 or 2, R ¹ represents a C _{1 to} C ₈ substituted or unsubstituted alkyl group, or a benzyl group which may be substituted with a halogen atom, an alkoxy group or a nitro group. .)
Formula (II):

(Wherein, k is an integer of 1 or 2, R ² is a C _{3 to} C ₁₆ unsubstituted alkyl group, or a part or all of hydrogen atoms are halogen atoms, C _{3 to} C ₁₂ alicyclic hydrocarbon groups, A C ₁ -C ₆ alkoxy group, a cyano group, an optionally substituted phenyl group, an optionally substituted phenylalkoxy group or an optionally substituted phenylalkylcarbamate group Represents a substituted C ₁ -C ₆ alkyl group, provided that R ² is not the same group as R ^{1 in} formula (I).
Formula (III):

(Wherein R ³ is a methyl group, a benzyl group, or — (CH ₂ ) ₄ —NHX group (where X is a benzyloxycarbonyl group optionally substituted with a halogen atom or a C ₁ -C ₆ alkoxy group, a halogen atom) substituted C ₁ optionally -C ₆ alkylcarbonyl group atom, allyloxycarbonyl group, fluorenyl alkoxycarbonyl group, C ₁ -C ₆ alkyl group or a benzene sulfonyl group which may be substituted with a nitro group or, represents a C ₁ -C ₆ alkyloxycarbonyl group.) represents a.)
Formula (IV):

(In the formula, k is an integer of 1 or 2, R ⁴ is a C _{1 to} C ₁₂ alkoxy group, a C _{1 to} C ₁₂ alkyl group in which part or all of the hydrogen atoms are substituted with halogen atoms, or C ₁ to It represents C ₁₂ alkylcarbonyl group, m-number of ^{R 4} is selected from the same or different .l 6 to 12 integer, m is an integer of 1-3.)
Formula (V):

(In the formula, R ⁵ represents a hydrogen atom, a methyl group, —CH (OH) CH _{3, a} C _{3 to} C ₄ branched alkyl group, or — (CH ₂ ) _n —Z (where n is 1 to An integer of 4, Z is a hydroxy group, a mercapto group, a carboxy group, a methylsulfanyl group, an amino group, a substituted aryl group, an aminocarbonyl group, —NH—C (NH ₂ ) ═NH,

Or

Represents. ). )
[11] The poly α-amino acid is
(A) one or more units represented by formula (I);
(B) a poly α-amino acid containing a unit represented by formula (II), a unit represented by formula (III), and one or more units selected from units represented by formula (IV) A membrane switch according to [10] above.
[12] The above [10], wherein R ² is a C ₆ -C ₁₆ unsubstituted alkyl group, or a C ₁ -C ₆ substituted alkyl group in which a part or all of hydrogen atoms are substituted with a fluorine atom or a norbornyl group. Or the membrane switch of [11] description.
[13] The membrane switch according to the above [10] or [11], wherein R ² is an n-hexyl group, an n-dodecyl group, a 2-norbornylmethyl group, or a 2,2,2-trifluoroethyl group.
[14] The membrane according to any one of [10] to [13], wherein R ³ is a methyl group or a — (CH ₂ ) ₄ —NHX group (where X represents a benzyloxycarbonyl group). switch.
[15] The above, wherein R ⁴ is a C ₁ -C ₆ alkoxy group, a C ₁ -C ₁₂ alkyl group in which part or all of the hydrogen atoms are substituted with fluorine atoms, or a C ₃ -C ₉ alkylcarbonyl group [10] The membrane switch according to any one of [14].
[16] The membrane switch according to any one of [10] to [14], wherein R ⁴ is a methoxy group, a butoxy group, a hexyloxy group, a trifluoromethyl group, or an n-hexylcarbonyl group.
[17] The above [10], wherein R ⁵ is a hydrogen atom, 4-aminobutyl group, 4-hydroxybenzyl group, aminocarbonylethyl group, or — (CH ₂ ) ₃ —NH—C (NH ₂ ) ═NH. The membrane switch according to any one of to [16].
[18] The membrane switch according to [10] above, wherein the polyamino acid is a poly α-amino acid containing one or more units selected from glutamic acid, aspartic acid, lysine and derivatives thereof.
[19] The polyamino acid is a poly α-amino acid containing one or more units selected from glutamic acid methyl ester, glutamic acid benzyl ester, aspartic acid benzyl ester, and Nε-carbobenzoxy-L-lysine. The membrane switch according to [10] above.
[20] The poly α-amino acid is a γ-methyl-L-glutamic acid / γ-hexyl-L-glutamic acid copolymer, a γ-methyl-L-glutamic acid / γ-dodecyl-L-glutamic acid copolymer, or γ-benzyl. -L-glutamic acid / γ-dodecyl-L-glutamic acid copolymer, γ-methyl-L-glutamic acid / γ-2,2,2-trifluoroethyl-L-glutamic acid copolymer, γ-methyl-L-glutamic acid / Γ-2-norbornylmethyl-L-glutamic acid copolymer, γ-benzyl-L-glutamic acid / γ-2-norbornylmethyl-L-glutamic acid copolymer, γ-methyl-L-glutamic acid / γ -(6- (p-methoxyphenoxy) -1-hexyl) -L-glutamic acid copolymer, γ-methyl-L-glutamic acid / γ- (6- (p-hexylcarbonyl) Enoxy) -1-hexyl) -L-glutamic acid copolymer, γ-methyl-L-glutamic acid / γ- (10- (p-methoxyphenoxy) -1-decyl) -L-glutamic acid copolymer, γ-methyl -L-glutamic acid / γ- (6- (p-butoxyphenoxy) -1-hexyl) -L-glutamic acid copolymer, γ-methyl-L-glutamic acid / γ- (6- (p-hexyloxyphenoxy)- 1-hexyl) -L-glutamic acid copolymer, γ-methyl-L-glutamic acid / γ- (6- (3,5-bis (trifluoromethyl) phenoxy) -1-hexyl) -L-glutamic acid copolymer , .gamma.-methyl -L- glutamate / N ^epsilon - benzyloxycarbonyl -L- lysine copolymer, .gamma.-benzyl -L- glutamate / N ^epsilon - benzyloxycarbonyl -L Lysine copolymer, γ-methyl-L-glutamic acid / L-phenylalanine copolymer, γ-benzyl-L-glutamic acid / L-phenylalanine copolymer, and γ-benzyl-L-glutamic acid / L-alanine copolymer The membrane switch according to [10] above, which is one or more selected from the group consisting of:
[21] The membrane switch according to any one of [11] to [20], wherein the poly α-amino acid is a random copolymer.
[22] The membrane switch according to any one of [11] to [20], wherein the poly α-amino acid is a block copolymer.
[23] The membrane switch according to any one of [10] to [22] above, wherein the poly α-amino acid has a weight average molecular weight (Mw) of 1,000 to 5,000,000. .
[24] The above-mentioned [1], wherein the organic material arranged so that the gap between the conductor portions is filled or the gap is present is subjected to polarization treatment by applying a voltage between the conductor portions. The membrane switch according to any one of to [23].
[25] Any one or both of the first substrate and the second substrate are flexible substrates formed of a flexible material, and are described in any one of [1] to [24] above. Membrane switch.
[26] The above [1] to [1], wherein the first substrate, the second substrate, and the spacer are formed of a flexible material, and the entire membrane switch has flexibility. [24] The membrane switch according to any one of [24].
[27] The above [1] to [24], wherein an adhesive layer is interposed between one or both of the first substrate and the spacer and between the second substrate and the spacer. The membrane switch as described in any one of.
[28] The above [1] to [1], wherein an adhesive layer is interposed between the organic material arranged so that a gap or a gap exists in the gap between the conductor portions and the conductor portion. 27]. The membrane switch according to any one of [27].
[29] The above [1], wherein the first conductor portion, the second conductor portion, and the wiring circuit connected to the conductor portions are formed by printing on the first and second substrate surfaces. The membrane switch according to any one of to [28].
[30] The membrane switch according to any one of the above [1] to [29] is disposed along a surface layer of an article that receives pressure, thereby providing a function of generating a signal corresponding to the received pressure. Said article.

  In one aspect of the membrane switch of the present invention, a gap between contact points (conductor portions), which is a simple gap in a conventional membrane switch, is filled with an organic material exhibiting piezoelectricity (hereinafter also simply referred to as an organic material). (Aspect of FIG. 1). Further, in another aspect of the membrane switch of the present invention, the organic material is disposed between the two conductor portions so that a gap exists between the organic material and the conductor portion on one side (the embodiment of FIG. 5). ). These structures are arranged so that pressure is applied in the direction of closing both conductor parts (thickness direction of the first and second substrates) and there is a filling or gap between the conductor parts even though it is a membrane switch. Further, when the organic material is compressed, piezoelectricity is developed in the organic material and polarization corresponding to the magnitude of the pressure occurs. That is, when the organic material is deformed, electric charges are generated at both ends of the organic material due to the piezoelectric effect. Therefore, the generated electric charge can be taken out as an electric signal through the conductor portion. In other words, changes in electrical characteristics between conductors, such as small changes in current flowing into (or out of) conductors, changes in voltage between conductors, and changes in capacitance between conductors, are measured. By doing so, the voltage value, current value, and other parameters and signals that indicate the off-state in which pressure is not applied and the state in which pressure is applied are displayed in multiple steps (or steplessly) depending on the pressure. It becomes possible to obtain.

Also, the first and second substrates having larger areas are used, a plurality of conductor portions are arranged in a predetermined arrangement pattern on both substrate surfaces, and each conductor portion on both substrate surfaces is handled between the substrates. By forming an array structure in which a plurality of conductor part pairs are arranged on one plane and filling the gaps between the respective conductor part pairs with an organic material exhibiting piezoelectricity or with an air gap between them The pressure and load acting on each contact can be sensed separately, and the distribution of pressure and load in the surface can be known with a simple structure.
Furthermore, if flexible substrates (flexible substrates) are used as the first and second substrates, the entire membrane switch becomes a flexible sheet-like material, while freely bending the surface layers of various articles. It is also possible to arrange them along. This makes it possible to easily attach to curved structures such as beds and mats, such as beds and mats, and curved surfaces such as seats of vehicles such as automobiles, and to give these articles the function of generating signals in response to applied pressure. Can be granted.
As shown in FIG. 5, when the gap s1 is provided between the conductor portion 1a on one side and the organic material 4, the organic material 4 is pushed after the conductor portion 1a is displaced by the gap s1. Become.

FIG. 1 is a cross-sectional view schematically showing a structural example of the membrane switch of the present invention. In the figure, the ratios between the thicknesses of the layers and the ratios with the dimensions in the horizontal direction are exaggerated for explanation. Hatching is appropriately added only to necessary portions so that regions can be easily distinguished. The same applies to the other figures. A thick arrow in the figure indicates a load (pressing force) acting from the outside. FIG. 2 is a cross-sectional view showing an example of how to use the membrane switch of the present invention. FIG. 3 is a perspective view showing an exploded view of the main surface of each layer according to one aspect of the membrane switch of the present invention. Illustration of the thickness of the substrate and the conductor is omitted. The spacer is illustrated with a thickness so that it is easy to recognize that the through holes (3a1, 3a2) are holes. The conductors and wiring circuits provided on the second substrate 2 are drawn in broken lines because they are on the other side of the substrate. This figure is a diagram showing the correspondence between the layers in an easy-to-understand manner, and is not a diagram for limiting an assembling procedure for laminating separately formed films. FIG. 4 is a diagram schematically illustrating a state in which an organic material exhibiting piezoelectricity is arranged such that a gap or gap is present in a gap between conductor portions by screen printing. To make the figure easier to understand, the screen is separated from the spacer and drawn like a thick plate. FIG. 5 is a cross-sectional view schematically showing another example of the membrane switch of the present invention. FIG. 6 is a diagram schematically showing an example of forming conductors, circuits, etc. on the substrate in the membrane switch of the present invention. FIG. 7 is a diagram showing a configuration example of an external extraction circuit when the membrane switch of the present invention is used. FIG. 8 is a cross-sectional view schematically showing a configuration example of a terminal (connection example of a conductor portion and a terminal) for connecting each conductor portion on the substrate to the turning portion in the membrane switch of the present invention. FIG. 9 is a diagram schematically showing another configuration example of a conductor portion and a circuit on the substrate in the membrane switch of the present invention. FIG. 10 is a cross-sectional view illustrating the structure of a conventional membrane switch.

Hereinafter, the present invention will be described with reference to preferred embodiments thereof.
In the membrane switch of the present invention, the first conductor portion 1a is formed on the main surface of the first substrate 1 as shown in the structural examples in FIGS. 1 (a) to 1 (c) and FIGS. The second substrate 2 is provided on the main surface of the second substrate 2, and the first substrate 1 and the second substrate 2 are arranged so that the conductor portions (1 a, 2 a) face each other with a gap therebetween. The substrate 2 is stacked with a spacer 3 interposed therebetween.
In the present invention, the gap between the conductor portions (1a, 2a) in this switch structure is filled with an organic material 4 exhibiting piezoelectricity, as shown in FIG. 1, or in FIG. As shown in the structural example, the organic material 4 exhibiting piezoelectricity is arranged so that a gap s1 remains between the one conductor part (upper conductor part 2a in the figure) and the organic material 4.
With this unique structure, the electrical characteristics between the conductor parts (1a, 2a) are measured by the measuring part M1 of the external device M, as shown in the block diagram of FIG. (Or external load to compress the membrane switch in the thickness direction) and voltage value, current value, and other parameters and signals indicating the state where pressure is applied. In addition, it is possible to adopt a configuration in which an output corresponding thereto is transmitted to the control unit M2 of the external device and used for various purposes.

1 (a) and 5 (a), in order to make the first conductor portion and the second conductor portion face each other, the conductor portion 1a, rather than the opening area of the through hole 3a provided in the spacer 3, Since the area of 2a is larger, the outer peripheral edge of the conductor portion protrudes from the opening of the through hole 3a.
Here, the “through hole” provided in the spacer in the present invention refers to a space portion that penetrates the spacer in the thickness direction of the membrane switch for the purpose of making the first conductor portion and the second conductor portion face each other. . The through-hole may be [a space portion formed later by punching a sheet-like spacer or the like], [a space portion existing in the spacer from the beginning by resin molding or the like], or [the first portion] The space portion for making the conductor portion and the second conductor portion face each other is determined by design in advance, and as a result of the spacer material being disposed later in a portion other than the space portion, the remaining space portion] It may be [a space portion formed by photolithography by exposing and developing a photosensitive material]. Further, the through hole does not necessarily need to be completely surrounded by the spacer material at the side of the space portion of the through hole. For example, adjacent through holes may communicate with each other, communicate with a space provided in the spacer for other purposes (such as air escape or weight reduction), or the outer periphery of the spacer You may communicate with the external space on the side. Further, for example, since the portion where the spacer material exists is discrete as an independent support column, even when the remaining space portion is connected in a mesh shape, such a space portion is the through hole. Depending on the shape of the through hole, the through hole may also serve as a space portion such as a groove provided in the spacer for other purposes.
As in FIG. 10 (a), in FIG. 1 (a) and FIG. 5 (a), the conductor portion is drawn thick for the sake of explanation, but in reality the conductor portion is thin and the spacer is greatly compressed by the conductor portion. There is no such thing. In the embodiment of FIG. 1 (a), the organic material 4 is filled in the entire through hole. In the embodiment of FIG. 5 (a), there is a gap s1 between the organic material 4 and the conductor portion 1a. Yes.
In the mode of FIGS. 1B and 5B, the areas of the conductor portions 1a and 2a are smaller than the opening area of the through hole 3a provided in the spacer 3, and therefore the conductor portions pass through the spacer. It fits in the hole and faces it. In the embodiment of FIG. 1 (a), the organic material 4 is filled in the entire through hole. In the embodiment of FIG. 5 (a), there is a gap s1 between the organic material 4 and the conductor portion 1a. Yes.
In the mode of FIG. 1C and FIG. 5C, the areas of the conductor portions 1a and 2a are smaller than the opening area of the through hole 3a provided in the spacer 3, and these conductor parts are within the through hole of the spacer. Are confronted with each other. In the embodiment of FIG. 1 (a), the organic material 4 is filled between the opposing conductors. In the embodiment of FIG. 5 (a), there is a gap s1 between the organic material 4 and the conductor portion 1a. doing. In this case, from the viewpoint of ensuring electrical insulation, [the opening area of the through hole provided in the spacer 3]> [the contact area between the conductor portion and the organic material] ≧ [of the conductor portions 1a and 2a in the through hole] Area].
In the case of the embodiment of FIG. 1C, it is preferable that [the contact area between the conductor portion and the organic material]> [the area of the conductor portions 1a and 2a in the through hole].
The aspect shown in FIG. 1 (a) is preferable in that the opposing conductor portion occupies the entire opening of the through hole and the conductor area is wide, and the insulating property is easily secured. The aspect of FIG.1 (c) is preferable from the point that a spacer does not prevent the deformation | transformation to a direction.

As for the first and second conductor portions, not only one pair but also a plurality of pairs of conductor portions may be provided in an array like a general membrane switch, and the main surface is shown for each layer in FIG. A plurality of first conductor portions (1a1, 1a2) are provided in a predetermined arrangement pattern on the first substrate 1, and a plurality of second conductors are provided on the second substrate 2 in a corresponding arrangement pattern. It is good also as an array structure which provided a part (2a1, 2a2), made these conductor parts oppose each other in the space | gap, and arranged several conductor part pairs on the surface. The spacer 3 is interposed between the substrates so that a gap is secured between the conductor portions of each conductor portion pair, and the gap between the conductor portions of each conductor portion pair (in FIG. In the through holes 3a1, 3a2, the organic material 4 (not shown) exhibiting piezoelectricity is arranged so as to be filled or have voids.
In the case of the array structure as shown in FIG. 3, the spacer 3 also functions as a partition that electrically insulates the conductor portion pairs and the lead-out wires to the outside from each other.

In the case of the array structure as shown in FIG. 3, the arrangement pattern and pitch of the conductor portions on the substrate may be appropriately determined according to the application. For example, if the membrane switch is arranged on the surface layer of an article and a signal corresponding to the pressure of each part is obtained, the arrangement pattern of the conductor part is a network in which a square, a regular triangle, a regular hexagon, etc. are in the shape of a mesh. There is a pattern in which conductors are arranged at the intersections. In addition, the membrane switch has a keyboard with a predetermined key arrangement (keyboards of various electronic musical instruments (especially with a pressure sensitive function), computer keyboards, control units of various devices, input pads of game machines, etc.) If it is used as a switch, the arrangement pattern corresponding to the key arrangement may be used.
The distance between the centers of the conductor portions in the array structure varies depending on the scale of the product and is not limited, but is generally about 0.1 mm to 100 mm.

FIG. 6 schematically shows an example of an arrangement pattern of conductors and wirings formed on the substrate surface (conductor parts of each switch and wirings connected thereto). In the figure, the number of conductor portions is set to 4 for the sake of simplicity. The wiring path is an example.
The outer peripheral shape of the substrate may be any shape according to the application, such as a square, a rectangle, or a circle. Further, in addition to the outer peripheral shape, a connector portion 1c protruding locally to the outside as shown in FIG. 6A is provided, and necessary functions such as an external circuit (for example, the external device M shown in FIG. 2) are provided. Connection with a circuit having For the structure of the connector portion 1c and the configuration for connecting each switch and an external circuit, known techniques can be referred to.
For example, the wiring on the substrate is exposed (no resist protective film is provided), and the exposed wiring surface is plated with various metals such as Ni, Pd, Au, or surface treatment such as carbon paste. A mode in which a commercially available connector is mounted on a substrate by soldering or the like, a mode in which a connector on the membrane switch side and an external circuit are electrically connected by solder, conductive paste, anisotropic conductive film (hereinafter ACF), etc. Etc.

  The membrane switch and the external circuit of the present invention are not necessarily separated from each other. As shown in FIG. 6B, the necessary external circuit m is directly formed or mounted on the substrate of the membrane switch. May be. The external circuit m in FIG. 6B may include a wiring portion and a large number of elements mounted thereon, or may be a single IC chip that integrates them. When an IC chip is used as the external circuit m, a mode of mounting on the wiring on the substrate of the membrane switch (a mode in which the external circuit m in FIG. 6B becomes an IC chip as it is) is preferable.

  The external circuit m in FIG. 6B may be a wireless communication device for performing communication with an external device. In other words, the connection between the membrane switch and the external device is not necessarily a wired connection via the connector, and may be a wireless connection using radio waves or light.

When the connector part is provided in the membrane switch, as shown in FIG. 8 (a), the wirings 10a and 20a of the connector part provided on the first substrate 1 and the second substrate 2 are separately connected to the outside. You may connect with a circuit.
In FIG. 8, a connection relationship in which the first conductor portion 1a and the wiring 10a of the connector portion are connected to each other by a wiring pattern on the first substrate surface is represented by a one-dot chain line arrow. Similarly for the second substrate, the connection relationship by the wiring pattern on the substrate surface is represented by a one-dot chain line.
In the example shown in FIG. 8B, the wiring 10a on the first substrate is connected to the wiring 12a on the second substrate through the conductive connection medium 11a. It is connected to the wiring 13a. In the example of the figure, wirings (13a, 20a) for all the conductor portions (1a, 2a) on the first substrate 1 and the second substrate 2 are gathered in the connector portion on the second substrate. doing. An embodiment in which conductors are assembled on one side of the substrate surface as shown in FIG. 8B is preferable because the structure of the connector becomes simple.

A known connection technique can be used for electrical connection between the wiring on one substrate and the wiring on the other substrate.
For example, as shown in FIG. 8B, in a mode in which a conductive connection medium 11a is interposed between both wirings facing each other, a conductive adhesive, ACF, or the like can be used as the connection medium. ACF is a preferable connection medium in that wirings with fine pitches can be connected with high reliability.
Further, as shown in FIG. 9, the first and second conductor portions (1a, 2a) and the respective wirings (1b, 2b) are all formed in a predetermined pattern on one substrate, and These wirings may be extended to one connector portion 1c, and the one board may be folded into two at the folding line R to form the first and second boards. In this aspect, the wiring on one substrate and the wiring on the other substrate are entangled with each other by the wiring pattern exceeding the folding line R.

The measurement unit included in the external circuit shown in FIGS. 2 and 6 measures the voltage, charge, current, capacitance, resistance or change between the switches in the membrane switch, and acts on each switch. What is necessary is just to be able to output an external pressure or force (load) as a signal corresponding thereto. Especially, since the change amount according to the pressure and force which acts on a switch is large for an electric charge or an electrostatic capacitance, it is preferable to measure and output them. Moreover, since the signal of each switch is weak, it is preferable to incorporate an amplifier circuit in the measurement unit.
Known techniques can be used for the measurement circuit and the amplification circuit as described above. For example, a circuit as illustrated in FIG. 7 can be cited as a circuit that amplifies the charge generated in each switch, converts it into a voltage by an integration circuit, and outputs the voltage. In the example of FIG. 7, C _X represents the capacitance of each switch, V _out is the output voltage, and C ₁ and R ₁ are capacitors and resistors that are determined as appropriate.

Furthermore, it is preferable to incorporate an A / D conversion circuit in the measurement unit for the purpose of taking a signal converted into a voltage into a computer. A known method is used as the A / D conversion circuit, and examples include an integration type, a successive approximation type, a flash type, and an oversampling type.
Further, ancillary circuits such as a noise removal circuit, a Soya tower circuit, a filtering circuit, a counting circuit, a counting reset circuit, a display circuit, a storage circuit, a virtual ground circuit, and various compensation circuits may be added as necessary.

The first and second substrates are not particularly limited as long as they can support the conductor portion, and a conventionally known membrane switch substrate material or printed wiring substrate material is preferable. Examples of such materials include, but are not limited to, polyimide resins, polyester resins, epoxy resins, urethane resins, polystyrene resins, polyethylene resins, polyamide resins, polyamideimide resins, acrylonitrile-butadienes. -Styrene (ABS) copolymer resin, polycarbonate resin, silicone resin, fluorine resin, liquid crystal polymer, paper phenol (composite material with paper impregnated with phenol resin) and glass epoxy (made of glass fiber) A composite material such as a composite material obtained by impregnating an epoxy resin into a laminate of cloths is preferable.
Alternatively, either or both of the first and second substrates may be formed by applying and curing a liquid insulating material such as solder resist ink.

  The materials of the first and second substrates may be the same or different from each other. In order to mount along the curved surface or surface layer of the article, it is preferable that either one or both of the first and second substrates are formed of a flexible material. In order to impart flexibility to the entire membrane switch, it is preferable that both substrates are formed of a flexible material. Among the above-described materials, polyester resins are preferable because they are low in cost, have high transparency, and have appropriate flexibility. In addition, a polyimide-based resin is preferable in applications where heat resistance and dimensional stability are important and flexibility is important. The flexibility is preferably the flexibility of the material itself, but includes a material in which the flexibility of the entire substrate is realized by adjusting the thickness of the substrate.

The thickness of each of the first and second substrates may be determined according to the scale of the product, the mechanical strength of the material, flexibility, elasticity, etc., and is not particularly limited. There is a problem that the organic material in each switch is not accurately transmitted, and if it is too thin, the switch is easily broken and the durability is lowered. In general, about 500 μm to 5 μm is generally used, and about 200 μm to 10 μm is a more practical and preferable range. For example, when the material of the first and second substrates is polyester, about 100 μm to 20 μm is a practically preferable range.
The first and second substrates may have the same thickness or different thicknesses. For example, one substrate may be a thicker dimension on the fixed side and the other substrate may be a thinner dimension on the movable side.
The outer peripheral shape of the first and second substrates may be appropriately determined according to the number of conductor pairs required, the arrangement pitch of the conductor pairs, and the size of the article to which the membrane switch is to be applied. Or a different shape.

  When a material having flexibility is used for the first or second substrate, the flexibility of the material is not particularly limited. For example, in the tensile test method defined in JIS K7161, JIS K7162, It is preferable that the rate is less than 1 GPa and the tensile fracture strain is 10% or more.

The material of the first and second conductor parts is arranged so that there is a filling or gap between the conductor parts, in addition to the conductive material used as a contact material of a conventionally known membrane switch or the wiring material of the printed wiring board. Any conductive material that can preferably transmit the change in polarization of the organic material to the outside may be used.
As such a conductive material, a preferable material is a single metal of a good conductor such as gold, silver, copper, platinum, lead, tin, nickel, chromium, or an alloy made of two or more kinds of metals selected from these metals. As mentioned. Also, conductive pastes, conductive inks, and conductive polymer inks containing polythiophene as the main component, which contain the above-mentioned metal fine particles (for example, metal nanoparticles) and carbon particles at a high concentration, are printed. As a preferred embodiment of the conductor portion, a material deposited on the substrate by drying, dried, cured, fired, or the like can be cited. In addition, transparent metal oxides such as indium tin oxide (ITO) and fluorine-doped tin oxide (FTO) are also preferable materials when the entire membrane switch is intended to be transparent.

  The surface of the conductive part and the circuit part may be subjected to a known surface modification for the purpose of wear resistance, rust prevention and adhesion improvement, or the formed conductive part may be used as it is. Known surface modifications include plating with Ni, Pd, Au, etc., and antirust treatment using a non-moving body layer or an organic layer.

The outer peripheral shape of each conductor portion is not particularly limited, and examples thereof include a square, a rectangle, and other polygons in addition to a circle as shown in FIG. The circular shape is a preferable shape from the viewpoint of manufacturing cost, crack prevention, and force sensing.
It is preferable that the outer peripheral shapes of the first and second conductor portions constituting the conductor portion pair are in a coincident relationship when one is projected onto the other. However, the lead-out wiring (corresponding to 2 in FIG. 6) through the conductor portion and the external circuit is not limited to this.
The size of the outer peripheral shape of each conductor part (area occupied by the main surface of the substrate) may be appropriately determined according to the scale and use of the membrane switch. For example, when the outer peripheral shape is circular, the diameter is About 0.1 μm to 500 mm is preferable, and 0.1 mm to 100 mm is more preferable. When the outer peripheral shape of the conductor is other than a circle, the size is preferably an area corresponding to a circular area having a diameter of about 0.1 μm to 500 mm, and an area corresponding to a circular area of about 0.1 mm to 100 mm. More preferred.
The thickness of each conductor portion varies depending on the scale of the product, the material, and the forming method, but is generally about 0.1 μm to 100 μm, and for example, a conductive paste or conductive ink is formed by printing. In this case, the thickness is preferably about 5 μm to 50 μm. When formed by metal foil or plating, about 5 μm to 50 μm is preferable, and when formed by vapor deposition or sputtering, 10 nm to 5 μm is preferable.
The distance between the conductor portions may be a value that can preferably detect the piezoelectricity of the organic material, but is preferably smaller from the viewpoint of flexibility and usability, from the viewpoint of ensuring insulation. Larger is preferable. The distance is preferably 3 μm to 500 μm, and more preferably 5 μm to 100 μm.

  As shown in FIG. 3, when a plurality of conductor part pairs are provided to form an array structure, one conductor part of each conductor part pair is not a separate and independent conductor part but a common potential. It may be a single conductor layer connected to each other and spreading on the substrate surface. Even if it is such an aspect, if the other conductor part is isolate | separated independently and insulated from each other, it will become an array structure in which the several conductor part pair was arranged.

As a method for forming the respective conductor portions on the first and second substrates, a contact forming method in a conventionally known membrane switch or a wiring circuit forming method in a printed wiring board may be used, which will be exemplified below. Such additive methods, semi-additive methods, and subtractive methods.
A method in which a conductive paste or conductive ink is deposited on a substrate so as to have the shape of a conductor portion by printing, and then dried, cured, fired, etc. to form a conductor portion.
A method in which a seed layer is formed by electroless plating, sputtering, vapor deposition, etc., and then a wiring is formed by electroplating using a resist to remove an unnecessary seed layer.
A method of leaving a conductor portion by etching a conductor layer formed on the entire surface by bonding a metal foil onto a substrate, sputtering of metal or ITO, vapor deposition, or the like.
Among these methods, the subtractive method is a preferable method from the viewpoint of the balance between productivity (low cost) and reliability.
The first conductor portion and the second conductor portion may be made of the same material or different materials.

The first and second substrates are provided with wiring circuits for connecting each conductor portion and an external circuit. In the example of FIG. 3, the first substrate 1 is provided with wiring circuits (1b1, 1b2) respectively connected to the conductor portions (1a1, 1a2), and the second substrate 2 is provided with the conductor portions (2a1, 1a2). Wiring circuits (2b1, 2b2) respectively connected to 2a2) are provided.
The wiring circuit may be formed not only on the surface on which the conductor portion is formed, but also on the back surface or inside the substrate. In that case, a conductive path, a through hole, a via, or the like that connects the wiring circuit and the conductor portion is formed on the substrate. Are provided in the thickness direction.
The material and forming method of the wiring circuit may be the same as the material and forming method of the conductor part described above. From the viewpoint of productivity and simple structure, it is preferable to form the conductor portion and the wiring circuit at the same time by the same forming method using the same material on the same surface of the substrate.

An example of forming the conductor portion and the wiring circuit on the first and second substrates using a printing method is as follows:
By using a film made of polyethylene terephthalate as a substrate and screen printing using a silver paste for a printed circuit, a conductor portion and a wiring circuit pattern connected thereto are drawn on the substrate. The substrate on which the conductor portion and the wiring circuit are drawn is heated and dried in an oven for a predetermined time to obtain a substrate on which the conductor portion and the wiring circuit are provided. This method has an excellent balance between productivity (low cost) and reliability.

An example of forming the conductor portion and the wiring circuit on the first and second substrates using photolithography is as follows:
Prepare a three-layer type polyimide copper clad laminate (a three-layer laminate in which a copper foil is laminated on a polyimide resin film via an adhesive layer (such as an epoxy adhesive layer)), and a dry film on the copper foil surface. The resist is laminated, and exposure / development is performed so that only the conductor portion and the wiring circuit to be formed are covered with the dry film resist. This is etched with iron chloride or copper chloride to remove the exposed copper foil, leaving only the intended conductor and wiring circuit. Finally, the dry film resist is peeled off to obtain a substrate provided with a conductor portion and a wiring circuit. This method is suitable for the manufacture of products that emphasize quality, because copper foil is a good conductor with excellent electrical and mechanical properties, has high adhesion to the substrate, has high heat resistance, and allows fine pattern processing. Yes. Further, since the surface of the wiring circuit is flat, it is advantageous in that insulation can be secured even if the organic material layer exhibiting piezoelectricity is thin.

  Any spacer may be used as long as it is interposed between the first and second substrates and can support the first and second substrates so as to form a gap between the conductor portions. The spacer is a mode in which the spacer surrounds and surrounds the gap between the conductor portions in an annular shape (that is, the film serving as the spacer has a through hole 3a as shown in FIGS. 1 (a) to (c), If the conductor portions are opposed to each other with the space portion in the through hole interposed therebetween, the formation of the spacer is simple, and the first and second substrates can be supported in a balanced manner. It is preferable because it can be insulated. However, it may be discretely provided as independent struts around one conductor portion pair. In this case, as described above, the space portion where the spacer material does not exist is a through hole.

The material of the spacer may be a rigid body, but it is moderately elastic and flexible from the viewpoint that the spacer does not hinder the pressure applied to the conductor part and that the membrane switch can be given flexibility. It is preferable to have low elasticity so that it can be compressed even with a small force.
The elasticity and flexibility of the spacer material are not particularly limited. For example, in the tensile test method defined in JIS K7161 and K7162, the tensile elastic modulus may be less than 1 GPa and the tensile strain may be 10% or more. preferable.
In addition, the spacer material is preferably an insulating material in order to electrically insulate adjacent conductor portion pairs from each other.
Examples of such materials include polymer materials such as polyester, polycarbonate, polyimide, vinyl chloride, and polyurethane. From the viewpoint of flexibility, elastic modulus, cost, and heat resistance, polyester is more preferable. .
The spacer material may be a cured liquid insulating material such as solder resist ink, or the same material as the liquid insulating material such as solder resist ink used for the substrate.

The opening shape of the through-hole provided in the spacer is not particularly limited, but in the case of FIGS. 1B and 1C, it is preferable that the shape is similar to the outer shape of the conductor portion. In addition to the circular shape shown in FIG. 3, preferred shapes include a square, a rectangle, a polygon, and an irregular shape. A passage for venting air when injecting an organic material exhibiting piezoelectricity may be connected to the through hole provided in the spacer.
The thickness of the spacer may be appropriately determined in consideration of the thickness of the conductor portion so that the distance between the conductor portions determined by design can be obtained. For example, in the example of FIG. 1, (thickness of spacer) = (thickness of conductor portion × 2) + (distance between conductor portions).

The conductor portion and the organic material do not necessarily have to be in close contact with each other, and there may be a gap s1 as shown in FIG. In this case, (spacer thickness)> (conductor portion thickness × 2) + (organic material thickness).
As described above, the distance between the conductor portions is preferably 3 μm to 500 μm.

The formation method of the spacer 3 including the through holes 3a1 and 3a2 as shown in FIG. 3 is not particularly limited, but the following method is exemplified.
A method of forming a sheet-shaped molded part having a through-hole using a resin mold such as extrusion molding or injection molding.
A method in which a film having a target thickness made of a spacer material is prepared and a through hole having a predetermined opening shape is formed by punching at a predetermined position to form a spacer (a method exemplified in (A) described later).
A method in which ink made of an insulating material is printed on a region on which a spacer on the first or second substrate on which a conductor part or a wiring circuit is formed is to be provided and cured to form a spacer. At this time, it is necessary to print the ink so as to leave an opening corresponding to the through hole. However, the opening may be provided by pattern formation using a known printing method such as screen printing, gravure coating, ink jet or the like. Good (the method illustrated in (B) described later). Further, the ink may be provided by performing exposure and development after printing the entire surface by roll coating using a photosensitive material, and removing the ink later.
Among the above methods, from the viewpoint of productivity and cost, a film having a desired thickness (necessary thickness as a spacer) made of a spacer material is prepared, and a through hole having a predetermined shape is formed by punching at a predetermined position. The spacer method is preferred, but the dimensional accuracy tends to be somewhat rough due to the process of removing a film having flexibility and elasticity with a mold. On the other hand, the method of forming the spacer by pattern printing or exposure / development is expensive compared to the method of removing the material cost and processing time, but it is higher on the printed surface than the above punching. There is an advantage that a fine structure can be formed as compared with punching or the like that provides close contact.

As a method of assembling the membrane switch when the spacer is formed as a separate sheet-like molded part by molding, molding, punching, etc., a known lamination technique can be referred to, and the spacer is placed between the spacer and the substrate. Examples thereof include a method of laminating them with an adhesive layer interposed, and a method of bonding them by punching.
The adhesive may be any of pressure sensitive adhesives, photosensitive adhesives, thermosetting adhesives, etc. Preferred materials include thermoplastic resins, epoxy resins, acrylic resins, silicone resins, polyimide resins. Natural rubber, synthetic rubber and the like.
Further, the portion to be bonded using an adhesive may be the entire surface, or a partial region of the spacer.

(A) A more specific production example of the membrane switch in the case where the spacer is formed as a separate sheet-like molded part and bonded to the substrate is as follows:
As a spacer, a 5-layer laminate in which (a release sheet for bonding, an adhesive layer, a layer made of polyethylene terephthalate as a spacer, an adhesive layer, a release sheet for matching) is laminated in this order is prepared. Is punched to form a desired through hole. What is necessary is just to determine the magnitude | size and position of a through-hole according to the magnitude | size and position of the predetermined space which should be formed between the conductor parts which oppose.
Next, the release sheet on one side is peeled off, and bonding is performed so that the contact point on one substrate and the opening of the through hole formed in the spacer coincide.
Next, it fills with the organic material which shows piezoelectricity in the through-hole of a spacer, or arrange | positions so that a space | gap may exist.
Next, the release sheet on the other surface of the spacer is peeled off, and the conductor portion on the other substrate and the opening portion of the through hole formed in the spacer are aligned and bonded to obtain the membrane switch.

(B) An example of forming the spacer when the spacer is formed on the substrate by printing is as follows:
An insulating ink layer is formed on one substrate surface on which the conductor portion and the wiring circuit are provided so as to surround the periphery of the conductor portion by screen printing, thereby forming a through hole. This is dried and cured for a predetermined time in an oven to obtain a spacer laminated on the substrate.
In this case, as described above, an insulating material such as solder resist ink may be used as the spacer material.

In the present invention, the organic material exhibiting piezoelectricity disposed so that there is a filling or void between conductor portions may be a single material, a mixed material, or a composite material. In the case of a mixed material or a composite material, It is not always necessary that the individual substances as the components have piezoelectricity, and it is sufficient that the material is an organic material exhibiting piezoelectricity as a whole. Specifically, the following materials (a) to (c) are mentioned.
(A) An organic piezoelectric body (single material or mixed material) having piezoelectricity itself.
(B) By using an organic piezoelectric body having piezoelectricity as a base material, and fillers made of other materials having the piezoelectricity itself dispersed therein, the piezoelectricity of the base material itself is different as a whole. A composite material that is an organic material that exhibits piezoelectricity.
(C) A composite material in which an organic material having no piezoelectricity is used as a base material, and fillers made of a material having piezoelectricity are dispersed therein, thereby forming an organic material exhibiting piezoelectricity as a whole.

The organic piezoelectric material (a) is composed of (a1) an organic compound that exhibits piezoelectricity from the chemical structure of the molecule, and (a2) no piezoelectricity from the chemical structure of the molecule. It is a concept that includes both organic compounds that can exhibit piezoelectricity by adding processing that does not change the structure.
The organic piezoelectric material is an organic compound, and therefore has flexibility and molding processability not found in inorganic materials such as lead zirconate titanate (PZT), which is known as a general ferroelectric. Moreover, it is lightweight and excellent in cost (see Japanese Patent Publication No. 62-4873).
Furthermore, PZT, which is a general inorganic ferroelectric material, contains a lot of lead harmful to the human body and the environment, but the organic piezoelectric material does not contain lead, and therefore has an advantage that the influence on the human body and the environment is small.
However, organic piezoelectric materials, especially organic ferroelectrics, have many reports on ferroelectricity, but many studies have not yet been made on the structure of the device, and the devices being studied have a complicated structure and are extremely The cost is high (refer to JP-A-10-332509 and JP-A-2009-53109). Further, there has been little study on an element having a structure that separately senses pressure applied to a plurality of points in a plane using an organic piezoelectric material.

Examples of the organic compound (a1) include polyvinylidene fluoride, vinylidene fluoride / trifluoroethylene copolymer, polyamino acid, polylactic acid, glycine sulfate, polyurea, nylon, ferroelectric liquid crystal, and crophonic acid. These may be any one kind or a mixture of two or more kinds. Examples of the organic compound (a2) include porous resins such as porous polyolefin (for example, a porous resin described in JP2012-124434A).
Among these organic piezoelectric materials, polyamino acid is a particularly preferable material from the viewpoint of good workability that it can be arranged so that there is a filling or void between conductor portions by a printing technique and good piezoelectric properties. Details of preferred polyamino acids will be described later.

The composite material of (b) as an organic material exhibiting piezoelectricity has the organic piezoelectric body of (a) as a base material, and particulate fillers made of another material having further piezoelectricity are dispersed therein. Is. Examples of the filler material include the organic piezoelectric material (a) (material different from the base material), lead zirconate titanate (PZT), natural or artificial quartz, lithium niobate (LiNbO ₃ ), niobium tantalate. Examples thereof include inorganic ferroelectrics such as potassium oxide [K (Ta, Nb) O ₃ ], barium titanate (BaTiO ₃ ), lithium tantalate (LiTaO ₃ ), and strontium titanate (SrTiO ₃ ).
For the particle diameter of the filler, for example, a ferret diameter (interval between two parallel lines in a certain direction sandwiching the particles) of a particle image obtained by a microscope may be adopted as the particle diameter (also referred to as a constant direction diameter). . The particle size of the filler is not particularly limited, but is preferably one that does not hinder the elasticity of the base material and the fluidity before curing, and examples include an average particle size of about 100 nm to 5 μm.
The content of the filler in the composite material is not particularly limited. However, when the content is small, the piezoelectricity is not expressed, and when the content is large, the flexibility and workability as an organic material are impaired. For this reason, 5-90 weight% is preferable and 10-80 weight% is more preferable.

The composite material of (c) as an organic material exhibiting piezoelectricity is a material in which an organic material not having piezoelectricity is used as a base material, and the same filler as in (b) is dispersed therein. The organic material that does not have piezoelectricity may be a general resin, an elastomer, and the like, for example, a thermosetting resin such as an epoxy resin, an acrylic resin, a phenol resin, and a polyurethane resin, natural rubber, acrylic rubber, and nitrile rubber. And elastomers such as butadiene rubber.
The content of the filler in the composite material is not particularly limited. However, when the content is small, the piezoelectricity is not expressed, and when the content is large, the flexibility and workability as an organic material are impaired. For this reason, 5-90 weight% is preferable and 10-80 weight% is more preferable.

  The organic material exhibiting piezoelectricity (the organic piezoelectric bodies (a) to (c) described above) is not limited to the various resins other than those described above as long as the effects as a piezoelectric body and a ferroelectric body are exhibited. Additives can optionally be included for property modification. Examples of resin additives include inorganic fillers such as silica, talc, and barium sulfate, colorants such as pigments and dyes, organic fillers such as carbon black, silicon powder, nylon powder, fluorine powder, and rubber particles, orbene and benton. Thickeners such as silicone, fluorine, polymer defoamer or leveling agent, epoxy resin, acrylic resin, phenol resin, polyurethane resin, maleimide compound, bisallyl nadiimide compound, vinyl benzyl resin, vinyl Examples thereof include thermosetting resins of benzyl ether resins, adhesion imparting agents such as triazole compounds, thiazole compounds, triazine compounds and porphyrin compounds.

The organic material contained between the conductors of the membrane switch according to the present invention may be subjected to pretreatment for developing piezoelectricity or polarization treatment for enhancing piezoelectricity.
Examples of the pretreatment for developing piezoelectricity include a treatment for trapping charges due to corona discharge or the like. Examples of the polarization process include a process in which a DC voltage is applied for a certain period of time using a high-voltage DC constant voltage power source or the like between both conductor portions sandwiching an organic material. Further, the polarization treatment may be performed without heating (for example, at a room temperature of about 5 ° C. to 35 ° C.) or under heating. When the polarization treatment is performed under heating, the heating temperature is preferably about the glass transition point of the target organic material. When the organic material is a composite material, although depending on the combination of the materials, the glass transition point of the organic material serving as the base material is a preferable heating temperature.

  The external force that can be detected by the membrane switch according to the present invention can be changed according to the size of each part of the membrane switch, such as the distance between the conductor parts and the contact area between the conductor part and the organic material. In a general application where the membrane switch is useful, the pressure range to be detected is about 0 MPa to 0.1 MPa.

[Poly α-amino acid]
The poly α-amino acid that is particularly preferable as the organic piezoelectric body (a) will be described in detail below.

  Such poly α-amino acids are glycine, alanine, valine, leucine, isoleucine, arginine, asparagine, aspartic acid, cystine, cysteine, glutamine, glutamic acid, histidine, lysine, ornithine, serine, threonine, tryptophan, methionine, phenylalanine, tyrosine and Any poly α-amino acid containing one or more units selected from the derivatives thereof may be used. Among them, poly α-amino acids containing one or more units selected from arginine, asparagine, aspartic acid, glutamine, glutamic acid, histidine, lysine, serine, threonine, tryptophan, tyrosine and derivatives thereof are preferable from the viewpoint of solubility. More preferable examples include homopolymers and copolymers of poly α-amino acids containing one or more units selected from glutamic acid, aspartic acid, lysine and derivatives thereof.

The following poly α-amino acids are preferred from the viewpoints of solubility and piezoelectric properties.
Formula (I):

(In the formula, k represents an integer of 1 or 2, R ¹ represents a C _{1 to} C ₈ substituted or unsubstituted alkyl group, or a benzyl group which may be substituted with a halogen atom, an alkoxy group or a nitro group. )) (Hereinafter also abbreviated as “unit of formula (I)”),
Formula (II):

(In the formula, k is an integer of 1 or 2, R ² is a C _{3 to} C ₁₆ unsubstituted alkyl group, or a part or all of the hydrogen atoms are halogen atoms, C _{3 to} C ₁₂ alicyclic hydrocarbon groups. , C ₁ -C ₆ alkoxy group, a cyano group, which may have a substituent phenyl group, which may have an optionally substituted phenylalkoxy group or a substituent phenyl carbamate group Represents a C ₁ -C ₆ alkyl group substituted with R ² , wherein R ² is not the same group as R ^{1 in} formula (I) (hereinafter referred to as “formula (II)”. Abbreviated as "unit"),
Formula (III):

(Wherein R ³ is a methyl group, a benzyl group, or — (CH ₂ ) ₄ —NHX group (where X is a benzyloxycarbonyl group optionally substituted with a halogen atom or a C ₁ -C ₆ alkoxy group, a halogen atom) substituted C ₁ optionally -C ₆ alkylcarbonyl group atom, allyloxycarbonyl group, fluorenyl alkoxycarbonyl group, C ₁ -C ₆ alkyl group or a benzene sulfonyl group which may be substituted with a nitro group or, Represents a C ₁ -C ₆ alkyloxycarbonyl group.)) (Hereinafter also abbreviated as “unit of formula (III)”),
Formula (IV):

(In the formula, k is an integer of 1 or 2, R ⁴ is a C _{1 to} C ₁₂ alkoxy group, a C _{1 to} C ₁₂ alkyl group in which part or all of the hydrogen atoms are substituted with halogen atoms, or C ₁ to C ₁₂ alkyl group, m-number of ^{R 4} is an integer of good .l be the same or different 6 to 12, m is. represents an integer of 1 to 3) units represented by (hereinafter, "the formula (Abbreviated as “unit of (IV)”), and formula (V):

、または

を表す。）を表す。）で表される単位（以下、「式（Ｖ）の単位」とも略称する。）
から選択される１種以上の単位を含有するポリα−アミノ酸である。(In the formula, R ⁵ represents a hydrogen atom, a methyl group, —CH (OH) CH _{3, a} C _{3 to} C ₄ branched alkyl group, or — (CH ₂ ) _n —Z (where n is 1 to An integer of 4, Z is a hydroxy group, a mercapto group, a carboxy group, a methylsulfanyl group, an amino group, a substituted aryl group, an aminocarbonyl group, —NH—C (NH ₂ ) ═NH,

Or

Represents. ). ) (Hereinafter also abbreviated as “unit of formula (V)”)
It is a poly α-amino acid containing one or more units selected from

Hereinafter, each of the units of formula (I) to formula (V) will be described in detail.
[Units of Formula (I)]
The unit of formula (I) is a glutamic acid γ-ester unit or an aspartic acid γ-ester unit.
R ¹ in the formula represents a C _{1 to} C ₈ substituted or unsubstituted alkyl group, or a benzyl group which may be substituted with a halogen atom, an alkoxy group or a nitro group.
"Alkyl group of _C 1 -C _8" is a linear or branched alkyl group, e.g., methyl group, ethyl group, n- propyl group, n- butyl group, n- pentyl group, n- Hexyl, n-heptyl, n-octyl, isopropyl, sec-butyl, tert-butyl, 2-methylbutyl, 3-ethylbutyl, 4-ethylbutyl, 2-methylpentyl, 3-methyl Pentyl group, 4-methylpentyl group, 5-methylpentyl group, 2-methylhexyl group, 3-methylhexyl group, 4-methylhexyl group, 5-methylhexyl group, 6-methylhexyl group, 3-ethylhexyl group, 4-ethylhexyl group, 5-ethylhexyl group, 6-ethylhexyl group, 2-methylheptyl group, 3-ethylheptyl group, 4-propylheptyl group, 2, - dimethylbutyl group, 2,4-dimethylbutyl group, 4,4-dipropyl butyl, 2-methyl-3-ethylpentyl group, a 2,3,4-trimethylpentyl group. Preferably _C 1 -C ₆ alkyl group, more preferably a _C 1 -C ₃ alkyl group, particularly preferably a methyl group or an ethyl group, most preferably a methyl group.

The “C ₁ -C ₈ alkyl group” may be partially or wholly substituted with hydrogen atoms, but is preferably unsubstituted. When it has a substituent, examples of the substituent include a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.), an alkoxy group (preferably a C _{1 to} C ₆ alkoxy group (for example, a methoxy group, an ethoxy group, n -Propoxy group, n-butoxy group, n-pentyloxy group, n-hexyloxy group, methylenedioxy group and the like)).

In the “benzyl group optionally substituted with a halogen atom, alkoxy group or nitro group”, the “halogen atom” includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., among which a fluorine atom, A bromine atom or a chlorine atom is preferred. The “alkoxy group” is a linear, branched or cyclic alkoxy group, preferably a C _{1 to} C ₆ alkoxy group (eg, methoxy group, ethoxy group, n-propoxy group, n-butoxy group, n- A pentyloxy group, an n-hexyloxy group, a methylenedioxy group, and the like, more preferably a methoxy group, an ethoxy group, an n-propoxy group, and a methylenedioxy group, and particularly preferably a methoxy group.

  Preferred examples of the “benzyl group optionally substituted with a halogen atom, alkoxy group or nitro group” include p-bromobenzyl group, p-chlorobenzyl group, p-fluorobenzyl group, p-methoxybenzyl group, 2, Examples include 6-dimethoxybenzyl group, 3,4-methylenedioxybenzyl group, o-nitrobenzyl group, p-nitrobenzyl group, 2-nitro-4,5-dimethoxybenzyl group, and benzyl group. -Methoxybenzyl group, p-nitrobenzyl group and benzyl group are more preferable, and benzyl group is particularly preferable.

A preferred embodiment of R ¹ is a methyl group or a benzyl group.

[Unit of Formula (II)]
The unit of formula (II) is a glutamic acid γ-ester unit or an aspartic acid γ-ester unit.
R ² in the formula is a C _{3 to} C ₁₆ unsubstituted alkyl group, or a part or all of hydrogen atoms are halogen atoms, C _{3 to} C ₁₂ alicyclic hydrocarbon groups, C _{1 to} C ₆ alkoxy groups, C ₁ -C ₆ substituted with a cyano group, an optionally substituted phenyl group, an optionally substituted phenylalkoxy group or an optionally substituted phenylalkylcarbamate group Represents an alkyl group. However, R ² in the formula is not the same group as R ¹ in the formula (I).

The “C ₃ -C ₁₆ unsubstituted alkyl group” is a linear or branched alkyl group such as n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n- Heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, 3- Ethylbutyl group, 4-ethylbutyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, 5-methylpentyl group, 2-methylhexyl group, 3-methylhexyl group, 4-methylhexyl group, 5-methylhexyl group, 6-methylhexyl group, 3-ethylhexyl group, 4-ethylhexyl group, 5-ethylhexyl group, 6-ethylhexyl group, 4-propylhexyl 5-propylhexyl group, 6-propylhexyl group, 5-butylhexyl group, 6-butylhexyl group, 6-pentylhexyl group, 2-methylheptyl group, 3-ethylheptyl group, 4-propylheptyl group, 5-butylheptyl group, 6-pentylheptyl group, 7-hexylheptyl group, 2-methyloctyl group, 3-ethyloctyl group, 4-propyloctyl group, 5-butyloctyl group, 6-pentyloctyl group, 7- Hexyloctyl group, 8-heptyloctyl group, 2-methylnonyl group, 3-ethylnonyl group, 4-propylnonyl group, 5-butylnonyl group, 6-pentylnonyl group, 7-hexylnonyl group, 8-heptylnonyl group, 2- Methyldecyl group, 2-methylundecyl group, 2-methyldodecyl group, 2-methyltridecyl group, 2-methyl Tetradecyl group, 2-methylpentadecyl group, 3,3-diethylpropyl group, 2,3-dimethylbutyl group, 2,4-dimethylbutyl group, 4,4-dipropylbutyl group, 2-methyl-3-ethyl A pentyl group, a 2,3,4-trimethylpentyl group, a 2-methyl-3-propylhexyl group, and the like can be given.

Such _"C 3 _{-C 16} unsubstituted alkyl group", _"C 6 _{-C 16} unsubstituted alkyl group" is preferably _"C 6 _{-C 16} linear unsubstituted alkyl group" is more preferred, _"C 6 -C ₁₂ linear unsubstituted alkyl groups (ie, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, etc.) " Particularly preferred is an n-hexyl group or an n-dodecyl group.

“A part or all of hydrogen atoms are halogen atoms, C _{3 to} C ₁₂ alicyclic hydrocarbon groups, C _{1 to} C ₆ alkoxy groups, cyano groups, phenyl groups which may have substituents, substituents in C ₁ -C ₆ alkyl group "substituted by also phenyl carbamate group optionally having a phenyl alkoxy group or a substituent optionally having," C ₁ -C ₆ alkyl group ", straight A linear or branched alkyl group, for example, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, isopropyl group, sec-butyl group, tert- A butyl group, 2-methylbutyl group, 3-ethylbutyl group, etc. are mentioned. The “C ₁ -C ₆ alkyl group” is preferably “C ₁ -C ₃ alkyl group (for example, methyl group, ethyl group, n-propyl group, isopropyl group)”, more preferably methyl group or ethyl group.
Examples of the “halogen atom” include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and among them, a fluorine atom, a bromine atom and a chlorine atom are preferable.
The “C ₃ -C ₁₂ alicyclic hydrocarbon group” is a saturated or unsaturated alicyclic hydrocarbon group such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group. Group, cyclononyl group, cyclodecyl group, decahydronaphthyl group, norbornyl group, adamantyl group, isobornyl group and the like. “C ₃ -C ₁₂ alicyclic hydrocarbon group” is preferably “C ₆ -C ₈ saturated alicyclic hydrocarbon group (that is, cyclohexyl group, cycloheptyl group, cyclooctyl group, norbornyl group)”, more Preferred are a cyclohexyl group and a norbornyl group, and more preferred is a norbornyl group.
The “C ₁ -C ₆ alkoxy group” may be linear or branched, but is preferably a linear alkoxy group, and may contain an ether bond in the alkyl chain. For example, methoxy group, ethoxy group, n-propoxy group, n-butoxy group, n-pentyloxy group, n-hexyloxy group, n-methoxyethoxy group, n-ethoxyethoxy group, n-methoxyethoxyethoxy group and n -An ethoxy ethoxy ethoxy group is mentioned, Preferably it is a methoxy group, an ethoxy group, or n-propoxy group, More preferably, it is an ethoxy group.
The “optionally substituted phenyl group” is an unsubstituted phenyl group or a part or all of hydrogen atoms are halogen atoms (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), C _{1 to} C _6. A phenyl group substituted with an alkoxy group, such as a phenyl group, p-fluorophenyl group, p-chlorophenyl group, 3,5-difluorophenyl group, pentafluorophenyl group, o-methoxyphenyl group, m-methoxy; Phenyl group, p-methoxyphenyl group, p-ethoxyphenyl group, p-propoxyphenyl group, p-butoxyphenyl group, p-pentyloxyphenyl group, p-hexyloxyphenyl group, 3,5-dimethoxyphenyl group, 3 , 5-ethoxymethoxyphenyl group, 3,5-ethoxyethoxyphenyl group, 3,5-methoxyethoxyphenyl A phenyl group, a p-fluorophenyl group, a p-methoxyphenyl group, a p-hexyloxyphenyl group, and a 3,5-ethoxyethoxyphenyl group, more preferably a phenyl group, p- It is a methoxyphenyl group.
The “optionally substituted phenylalkoxy group” is an unsubstituted phenylalkoxy group or a part or all of hydrogen atoms are halogen atoms (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), C ₁ -C ₆ phenyl alkoxy group substituted with an alkoxy group such as, for example, benzyloxy group, phenylethoxy group, p- fluorobenzyloxy group, 3,5-difluorobenzyl group, p- methoxybenzyl group, 3 , 5-dimethoxybenzyloxy group, preferably benzyloxy group, phenylethoxy group, p-fluorobenzyloxy group, p-methoxybenzyloxy group, more preferably benzyloxy group, phenylethoxy group. .
An “optionally substituted phenylalkylcarbamate group” is an unsubstituted phenylalkylcarbamate group or a part or all of hydrogen atoms are halogen atoms (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), C A phenylalkyl carbamate group substituted with a _{1 to} C ₆ alkoxy group, such as a benzyl carbamate group, a p-fluorobenzyl carbamate group, a 3,5-difluorobenzyl carbamate group, a p-methoxybenzyl carbamate group, 3, 5 -Dimethoxybenzyl carbamate group, p-methoxybenzyl carbamate group, 3,5-dimethoxybenzyl carbamate group, phenylethyl carbamate group and phenylpropyl carbamate group are mentioned, and benzyl carbamate group is preferable.

A preferred embodiment of R ² is “C ₆ -C ₁₆ unsubstituted alkyl group, or C ₁ -C ₆ wherein some or all of the hydrogen atoms are substituted with halogen atoms or C ₃ -C ₁₂ alicyclic hydrocarbon groups”. A substituted alkyl group ", and a more preferred embodiment is a" C ₆ -C ₁₆ unsubstituted alkyl group, or a C ₁ -C ₆ substituted alkyl group in which some or all of the hydrogen atoms are substituted with fluorine atoms or norbornyl groups " Particularly preferred examples of R ² include an n-hexyl group, an n-dodecyl group, a 2-norbornylmethyl group, and a 2,2,2-trifluoroethyl group.

[Unit of Formula (III)]
The unit of formula (III) includes an alanine unit, a phenylalanine unit and a lysine derivative unit.
In the formula, R ³ represents a methyl group, a benzyl group or a — (CH ₂ ) ₄ —NHX group (where X is a benzyloxycarbonyl group which may be substituted with a halogen atom or a C _{1 to} C ₆ alkoxy group, a halogen atom) substituted C ₁ optionally -C ₆ alkylcarbonyl group atom, allyloxycarbonyl group, fluorenyl alkoxycarbonyl group, C ₁ -C ₆ alkyl group or a benzene sulfonyl group which may be substituted with a nitro group or, represents a C ₁ -C ₆ alkyloxycarbonyl group.) represents the.

In a lysine derivative unit, that is, a unit in which R ³ is a “— (CH ₂ ) ₄ —NHX group”,
The “C ₁ -C ₆ alkoxy group” which is a substituent when X is a “substituted benzyloxycarbonyl group” may be linear or branched, but is preferably a linear alkoxy group, The alkyl chain may contain an ether bond. For example, methoxy group, ethoxy group, n-propoxy group, n-butoxy group, n-pentyloxy group, n-hexyloxy group, n-methoxyethoxy group, n-ethoxyethoxy group, n-methoxyethoxyethoxy group and n -An ethoxyethoxy ethoxy group is mentioned.
Further, "C ₁ -C ₆ alkyl group" when X is a "C ₁ -C ₆ alkylcarbonyl group", and, X is a substituent when it is "substituted benzenesulfonyl group", "C ₁ ~ The “C ₆ alkyl group” is a linear or branched alkyl group, for example, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, isopropyl group. , Sec-butyl group, tert-butyl group, 2-methylbutyl group, 3-ethylbutyl group and the like.
The lysine derivative unit is preferably an N ^ε -benzyloxycarbonyl lysine unit in which R ³ is — (CH ₂ ) ₄ —NH—CO—CH ₂ —C ₆ H ₅ .

[Unit of Formula (IV)]
The unit of formula (IV) is a glutamic acid γ-ester unit or an aspartic acid γ-ester unit.
R ⁴ in the formula represents a C _{1 to} C ₁₂ alkoxy group, a C _{1 to} C ₁₂ alkyl group in which part or all of the hydrogen atoms are substituted with a halogen atom, or a C _{1 to} C ₁₂ alkylcarbonyl group, The m R ⁴ may be the same or different.
The “C ₁ -C ₁₂ alkoxy group” in R ⁴ is a linear or branched alkoxy group such as a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group, or an n-pentyloxy group. N-hexyloxy group, n-heptyloxy group, n-octyloxy group, n-nonyloxy group, n-decyloxy group, n-undecyloxy group, n-dodecyloxy group, isopropoxy group, sec-butoxy group , Tert-butoxy group, 2-ethylhexyloxy group, and tert-octyloxy group. Among them, C _{1 to} C ₆ alkoxy groups (for example, methoxy group, ethoxy group, n-propoxy group, n-butoxy group, n-pentyloxy group, n-hexyloxy group, isopropoxy group, sec-butoxy group, Or a tert-butoxy group or the like), and a methoxy group, an n-butoxy group, or an n-hexyloxy group is more preferable.

The “C ₁ -C ₁₂ alkyl group in which part or all of the hydrogen atoms are substituted with a halogen atom” is a linear or branched alkyl group, and examples of the halogen atom include a fluorine atom, a chlorine atom, bromine An atom and an iodine atom are mentioned, Preferably a fluorine atom is mentioned. Examples of the halogen-substituted alkyl group include a monofluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a trifluoroethyl group, a trifluorodimethylethyl group, a hexafluoroisopropyl group, a pentafluoroethyl group, a trifluorobutyl group, Pentafluorobutyl group, heptafluorobutyl group, nonafluorobutyl group, trifluoropentyl group, trifluoroheptyl group, trifluorooctyl group, trifluorononyl group, trifluorodecyl group, trifluoroundecyl group, trifluorododecyl group , Pentafluoropentyl group, heptafluoropentyl group, octafluoropentyl group, nonafluoropentyl group, dodecafluorohexyl group, tridecafluorohexyl group, heptadecafluorooctyl group, heny Safluoroundecyl group, heptadecafluoroundecyl group, henicosafluorodecyl group, henicosafluorododecyl group, trichloromethyl group, trichloroethyl group, tribromomethyl group, tribromoethyl group, triiodomethyl group, And a triiodoethyl group, among which a trifluoromethyl group or a trifluoroethyl group is preferable, and a trifluoromethyl group is more preferable.

The “C ₁ -C ₁₂ alkylcarbonyl group” is linear or branched, for example, methylcarbonyl, ethylcarbonyl, n-propylcarbonyl, isopropylcarbonyl, n-butylcarbonyl, isobutylcarbonyl, tert-butylcarbonyl , Sec-butylcarbonyl, n-pentylcarbonyl, isopentylcarbonyl, neopentylcarbonyl, n-hexylcarbonyl, isohexylcarbonyl, 3-methylpentylcarbonyl, n-heptylcarbonyl, n-octylcarbonyl, n-nonylcarbonyl, n Mention may be made of -decylcarbonyl, n-undecylcarbonyl and n-dodecylcarbonyl. Among _them, preferred is C 3 -C ₉ alkyl group, n- propyl carbonyl, isopropyl-carbonyl, n- butylcarbonyl, iso-butylcarbonyl, tert- butylcarbonyl, sec- butylcarbonyl, n- pentylcarbonyl, isopentyl carbonyl, neo Pentylcarbonyl, n-hexylcarbonyl, isohexylcarbonyl, n-heptylcarbonyl and n-octylcarbonyl are more preferred, and n-hexylcarbonyl is particularly preferred.

A preferred embodiment of R ⁴ is a C _{1 to} C ₆ alkoxy group, a C _{1 to} C ₁₂ alkyl group in which some or all of the hydrogen atoms are substituted with fluorine atoms, and a C _{3 to} C ₉ alkyl carbonyl group, and R ⁴ Particularly preferred examples of are methoxy group, n-butoxy group, n-hexyloxy group, trifluoromethyl group, and n-hexylcarbonyl group.

l represents an integer of 6 to 12, preferably an integer of 6 to 10. M represents an integer of 1 to 3, preferably 1 or 2, and when m is 2 or 3, two or three R ⁴ may be the same or different, but they are the same. preferable.

、または

を表す。）を表す。[Unit of Formula (V)]
R ⁵ in the formula is a hydrogen atom, a methyl group, —CH (OH) CH _{3, a} C _{3 to} C ₄ branched alkyl group, or — (CH ₂ ) _n —Z (where n is 1 to 4). , Z is a hydroxy group, a mercapto group, a carboxy group, a methylsulfanyl group, an amino group, a substituted aryl group, an aminocarbonyl group, —NH—C (NH ₂ ) ═NH,

Or

Represents. ).

The “C ₃ -C ₄ branched alkyl group” is preferably an isopropyl group or a sec-butyl group. _N in the “— (CH ₂ ) _n —Z group” is an integer of 1 to 4. Further, the “substituted aryl group” in Z is a phenyl group, a naphthyl group, or the like in which part or all of the hydrogen atoms are substituted with a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.) or a hydroxy group. 4-hydroxyphenyl group and phenyl group are preferable, and 4-hydroxyphenyl group is particularly preferable.

In a preferred embodiment of the unit of the formula (V), R ⁵ is a hydrogen atom, 4-aminobutyl group, 4-hydroxybenzyl group, aminocarbonylethyl group, or — (CH ₂ ) ₃ —NH—C (NH ₂ ) ═ It is a unit that is an NH group.

  The poly α-amino acid containing one or more units selected from the unit of the formula (I) to the unit of the formula (V) is a homocopolymer of the unit of the formula (I), a homo of the unit of the formula (II) Polymers, homopolymers of units of formula (III), homopolymers of units of formula (IV), and homopolymers of units of formula (V). In the case of a copolymer, a copolymer composed of two or more units of the units of the formula (I), a copolymer composed of two or more units of the units of the formula (II), a unit of the units of the formula (III) A copolymer consisting of two or more units, a copolymer consisting of two or more units of the units of formula (IV), a copolymer consisting of two or more units of the units of formula (V), and the formula ( Copolymers comprising units of two or more different formulas from units I) to units of formula (V) are included. The polymerization form of the copolymer may be a random copolymer or a block copolymer.

  In the poly α-amino acid, the α-amino acids constituting the units of the formulas (I) to (V) may be either L-form or D-form, but are preferably L-form.

  Specific examples of the homopolymer include poly (DL-alanine), poly (γ-methyl-L-glutamic acid), poly (γ-benzyl-L-glutamic acid), poly (L-arginine), and poly (L-lysine). , Poly (L-tyrosine), poly (L-glycine) and the like.

As a preferred embodiment of the copolymer,
A copolymer comprising two or more units of the unit of formula (I) (for example, γ-methyl-L-glutamic acid / γ-benzyl-L-glutamic acid copolymer (preferably γ-methyl-L-glutamic acid (5 95 mol%) / γ-benzyl-L-glutamic acid (5-95 mol%) copolymer)). (A): one or more units of the units of formula (I), and (B): a unit of formula (II), a unit of formula (III), and a unit of formula (IV) And copolymers containing one or more units. Particularly preferred embodiments are: (A): one or more units of units of formula (I), (B): units of formula (II), units of formula (III), and units of formula (IV) A copolymer comprising one or more units selected from:
In the copolymer containing the unit of (A) and the unit of (B), the unit of (A) is R ¹ in the formula (I) from the viewpoint that a better piezoelectric poly α-amino acid is obtained. A copolymer consisting of glutamic acid γ-benzyl ester units which are benzyl groups is particularly preferred. When the unit of (B) is a copolymer comprising the unit of formula (II) or the unit of formula (IV), the copolymer is preferably a random copolymer, and the unit of (B) is represented by formula (III) In the case of a copolymer consisting of the following units, the copolymer is preferably a block copolymer, and is a (A)-(B) type block copolymer or (A)-(B)-(A) type block copolymer. Is particularly preferred.

  The content of the unit (A) in all units of the copolymer containing the unit (A) and the unit (B) varies depending on the type of the unit (B), but is 0.01 mol% to 90 mol%. Is preferred. The upper limit is preferably 85 mol%, more preferably 80 mol%, and even more preferably 60 mol%. The lower limit is preferably 0.1 mol%, more preferably 1 mol%, still more preferably 5 mol%, still more preferably 10 mol%, still more preferably 15 mol%, still more preferably 20 mol%, and 40 mol%. Is more preferable.

  Moreover, although content of the unit of (B) changes with kinds of unit of (B), 10 mol%-99.99 mol% are preferable. The upper limit is preferably 99.9 mol%, more preferably 99 mol%, further preferably 95 mol%, further preferably 90 mol%, further preferably 85 mol%, further preferably 80 mol%, and 60 mol%. Is even more preferred. The lower limit is more preferably 15 mol%, further preferably 20 mol%, and still more preferably 40 mol%. When the unit of (B) is a unit of formula (IV), the lower limit is preferably 50 mol%, more preferably 60 mol%, and even more preferably 80 mol%.

  When the copolymer containing the unit of (A) and the unit of (B) is a copolymer composed of the unit of formula (I) and the unit of formula (II), for example, γ-methyl-L-glutamic acid (15 to 85 mol%) / γ-hexyl-L-glutamic acid (15-85 mol%) copolymer, γ-methyl-L-glutamic acid (40-60 mol%) / γ-dodecyl-L-glutamic acid (40-60 mol) %) Copolymer, γ-benzyl-L-glutamic acid (40-60 mol%) / γ-dodecyl-L-glutamic acid (40-60 mol%) copolymer, γ-methyl-L-glutamic acid (30-70) Mol%) / γ-2,2,2-trifluoroethyl-L-glutamic acid (30 to 70 mol%) copolymer, γ-methyl-L-glutamic acid (40 to 60 mol%) / γ-2-no Rubonylmethyl-L-glutami An acid (40 to 60 mol%) copolymer, or γ-benzyl-L-glutamic acid (40 to 60 mol%) / γ-2-norbornylmethyl-L-glutamic acid (40 to 60 mol%) copolymer. preferable.

In the case of a copolymer comprising the unit of the formula (I) and the unit of the formula (III), for example, γ-methyl-L-glutamic acid (20 to 80 mol%) / N ^ε -benzyloxycarbonyl-L-lysine (20 to 80 mol%) copolymer, .gamma.-benzyl -L- glutamic acid (40 to 60 mol%) / N ^epsilon - benzyloxycarbonyl -L- lysine (40-60 mol%) copolymer, .gamma.-methyl -L-glutamic acid (40-60 mol%) / L-phenylalanine (40-60 mol%) copolymer, γ-benzyl-L-glutamic acid (40-60 mol%) / L-phenylalanine (40-60 mol%) ) Copolymer or γ-benzyl-L-glutamic acid (40-60 mol%) / L-alanine (40-60 mol%) copolymer is preferred.

  In the case of a copolymer comprising the unit of formula (I) and the unit of formula (IV), for example, γ-methyl-L-glutamic acid (<1 mol%) / γ- (6- (p-methoxyphenoxy) -1-hexyl) -L-glutamic acid (> 99 mol%) copolymer, γ-methyl-L-glutamic acid (<1 mol%) / γ- (6- (p-hexylcarbonylphenoxy) -1-hexyl) -L-glutamic acid (> 99 mol%) copolymer, γ-methyl-L-glutamic acid (<1 mol to 16 mol%) / γ- (10- (p-methoxyphenoxy) -1-decyl) -L- Glutamic acid (84 to> 99 mol%) copolymer, γ-methyl-L-glutamic acid (<1 to 8 mol%) / γ- (6- (p-butoxyphenoxy) -1-hexyl) -L-glutamic acid (92 to> 99 mol%) Copolymer, γ-methyl-L-glutamic acid (<1 mol to 14 mol%) / γ- (6- (p-hexyloxyphenoxy) -1-hexyl) -L-glutamic acid (86 to> 99 mol%) Γ-methyl-L-glutamic acid (<1 to 8 mol%) / γ- (6- (3,5-bis (trifluoromethyl) phenoxy) -1-hexyl-L-glutamic acid (92 to>) 99 mol%) copolymer is preferred.

  The molecular weight of the poly α-amino acid is not particularly limited, but the weight average molecular weight (Mw) is preferably 1,000 to 5,000,000, preferably 5,000 to 5,000, from the viewpoint of piezoelectricity and film-forming property of the poly α-amino acid. 2,500,000 is more preferable, and 10,000 to 2,000,000 is more preferable.

  The preparation method of poly (alpha) -amino acid is not specifically limited, The manufacturing method of poly (alpha) -amino acid known per se is employable. In general, N-carboxy-α-amino acid anhydrides that are units of formula (I), units of formula (II), units of formula (III), units of formula (IV), or units of formula (IV) Or an N-carboxy-α-amino acid derivative anhydride appropriately mixed and dissolved or suspended in an organic solvent or water, and if necessary, a polymerization initiator may be added thereto for copolymerization. For example, when producing a copolymer containing the above unit (A) and the unit (B), N-carboxy-α-glutamic acid γ-methyl ester anhydride or N-carboxy-α- Glutamic acid γ-benzyl ester anhydride and (B) unit N-carboxy-α-amino acid anhydride or N-carboxy-α-amino acid ester derivative anhydride are mixed as appropriate and dissolved or suspended in an organic solvent or water. And a method in which a polymerization initiator is added thereto for copolymerization as necessary. When preparing a copolymer in which the unit of (B) is composed of the unit of formula (II) or the unit of formula (IV), N-carboxy-α-glutamic acid anhydride or N-carboxy-α-glutamic acid γ-ester anhydride Dissolve or suspend the product in an organic solvent or water, add a polymerization initiator to this if necessary, polymerize it, prepare poly α-glutamic acid or poly α-glutamic acid γ-ester, and then specify the raw material An appropriate amount of one or more alcohols is added to the glutamic acid unit of poly α-glutamic acid or poly α-glutamic acid γ-ester, a catalyst is added if necessary, and an ester is introduced at the γ position, or γ position The method of preparing by converting ester of this can be mentioned.

  Examples of the organic solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, tetrahydrofuran, diethyl ether, diisopropyl ether, petroleum ether, 1,4-dioxane, benzene, toluene, xylene, hexane, cyclohexane, ethyl acetate, butyl acetate. , Trifluoroacetic acid, acetic acid, formic acid, dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, trichloroethane, trichloroethylene, trifluoroethane, 1,1,1,3,3,3-hexafluoro-2-propanol, 2,2,2-trifluoroethanol, hexafluoroacetone, methanol, ethanol, 1-propanol, 2-propanol, formamide, N, N-dimethylformamide, N, N-dimethyl Acetamide, N- methylpyrrolidone, dimethyl sulfoxide, pyridine, acetonitrile, may be mentioned trimethylamine, triethylamine, and tributylamine. One or more organic solvents can be used in combination.

  Examples of the polymerization initiator include ethylenediamine, propylenediamine, hexamethylenediamine, 1,4-cyclohexanediamine, 1,2-cyclohexanediamine, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, and toluene-2. Primary amines such as methylamine, ethylamine and 1-propylamine; alcohol amines such as methanolamine, ethanolamine and diethanolamine; dimethylamine Secondary amines such as N, N-dimethylethylenediamine, and primary tertiary diamines such as N, N-dimethyl-1,3-propanediamine; Tertiary amines such as ethylene, triethylamine, and tributylamine; amino group-containing polymers such as polyether diamine and polyester diamine; primary alcohols such as methanol and ethanol; secondary alcohols such as isopropanol; ethylene glycol, propylene glycol, 1 , 4-butanediol, and glycols such as hexamethylene glycol; hydroxyl group-containing polymers such as polyether diol and polyester diol; thiols and the like. One or more polymerization initiators can be used in combination.

  Examples of the catalyst include hydrochloric acid, sulfuric acid, nitric acid, p-toluenesulfonic acid, sodium hydroxide, potassium hydroxide, sodium methoxide, sodium t-butoxide, potassium methoxide, potassium t-butoxide, potassium cyanide, carbon dioxide, Mention may be made of titanium (IV) tetraisopropoxide, 1,3-substituted tetraalkyldistannoxane tin (IV) complexes, tetracyanoethylene, 4-dimethylaminopyridine, and diphenylammonium triflate-trimethylsilyl chloride. One or more catalysts can be used in combination.

  The amount of catalyst is appropriately set depending on the reaction, but in general, an appropriate reaction time can be realized and can be appropriately selected within the range where it is not difficult to remove the catalyst after the reaction. For example, the number of moles of amino acid anhydride to be used 0.0001 to 1 equivalent, preferably 0.01 to 0.75 equivalent, more preferably 0.1 to 0.5 equivalent.

  The amount of alcohol used as a raw material is appropriately set depending on the reaction, but in general, it can be appropriately selected within a range in which side chain conversion is sufficiently performed and removal of unreacted alcohol is not difficult. -0.01-50 equivalent with respect to the glutamic acid unit of an amino acid, Preferably it is 0.1-25 equivalent, More preferably, it can be set as 0.15-20 equivalent.

For example, as shown in FIGS. 4 (a) and 4 (b), the organic material exhibiting piezoelectricity is filled in the gap between the conductor portions or disposed so that there is a gap. The part 2a and a wiring circuit (not shown) connected thereto are formed, and a spacer 3 having a through hole 3a is laminated thereon, and the upper surface of the conductor part 2a is exposed on the bottom surface in the through hole. In this state, a method of injecting an ink (or paste) 4a containing an organic material exhibiting piezoelectricity (such as the above-mentioned poly α-amino acid) into the through hole 3a by a printing method is exemplified.
4 (a) and 4 (b) are schematic diagrams showing an example of filling by screen printing, and the transmission port P1 formed in the screen P is aligned with the opening of the through hole 3a formed in the spacer 3, The squeegee Q moves in the direction of the arrow and rubs the screen, and the ink 4a of the screen P passes through the transmission port P1 and is pushed into the through hole 3a directly below. A wavy line P2 in the figure indicates a screen mesh and is exposed in the transmission port P1.
In the embodiment of FIG. 4A, the shape of the transmission port P1 formed in the screen P matches the opening shape of the through hole 3a formed in the spacer 3, and the entire inside of the through hole is filled with the ink 4a. ing. When a substrate having a conductor portion is laminated thereon, the membrane switch shown in FIG. 1A is obtained.
4B, the shape of the transmission port P1 formed in the screen P is smaller than the opening shape of the through hole 3a formed in the spacer 3, and only a specific region on the upper surface of the conductor portion 2a. Is filled with ink 4a. When a substrate having a conductor portion is laminated thereon, as shown in FIG. 1C, only a specific region (for example, a central region) between the conductor portions is filled with an organic material exhibiting piezoelectricity. Membrane switch is obtained.
The printing method may be not only the screen printing but also gravure printing, offset printing, flexographic printing, inkjet printing, and the like. In addition, a technique called soft lithography, such as microcontact printing or micromolding, is also included in the printing method.
A method of injecting an organic material exhibiting piezoelectricity into the through hole by printing is a preferable method from the viewpoint of cost, film thickness control, and the like.
In addition to printing, the piezoelectric material can be injected into the gap by bonding the molded or cut organic piezoelectric material via an adhesive or adhesive film, or by thermocompression bonding, or by injecting a molten material. The method etc. are mentioned.

When a poly α-amino acid-containing ink is used in the above printing method, various organic solvents can be used for the ink, such as chloroform, dichloromethane, methylene chloride, trichloroethylene, ethylene dichloride, 1,2-dichloroethane. , Fluorine-containing branched alcohols such as chlorohydrocarbon solvents such as tetrachloroethane and chlorobenzene, perfluoro-tert-butanol, hexafluoro-2-methylisopropanol, 1,1,1,3,3,3-hexafluoroisopropanol Solvents, nitrogen-containing polar solvents such as N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, alkyl ketone solvents such as acetone, methyl ethyl ketone, diethyl ketone, acetophenone, cyclohexanone, benzoic acid Benzoic acid ester solvents such as methyl, benzoic acid ether and butyl benzoate, aromatic hydrocarbon solvents such as benzene, toluene, xylene and solvent naphtha, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, triethylene glycol dimethyl ether, propylene Glycol ether solvents such as glycol monomethyl ether, methyl cellosolve acetate, methoxypropyl acetate, carbitol acetate, glycol ester solvents such as butyl carbitol acetate, dimethyl ether, diethyl ether, dipropyl ether, tetrahydrofuran, 1,4-dioxane, Ether solvents such as 1,3-dioxolane and methyl t-butyl ether, dimethyl sulfoxide, Sulfoxide / sulfone solvents such as dimethylsulfone, alcohol / phenol solvents such as methanol, ethanol, propanol, butanol, pentanol, ethylene glycol, propylene glycol, phenol, cresol, polyethylene glycol, normal hexane, cyclohexane, normal heptane, isooctane And hydrocarbon solvents such as normal decane.
One organic solvent may be used alone, or two or more organic solvents may be mixed and used.
Preferably, it is at least one selected from nitrogen-containing polar solvents, hydrocarbon ketone solvents, benzoate solvents, aromatic hydrocarbon solvents, glycol ether solvents, glycol ester solvents. In general, in the printing method, it is preferable to use a solvent having a boiling point of 150 ° C. or higher in order to prevent the ink from drying and the viscosity from changing during printing.

  The concentration of the poly α-amino acid in the poly α-amino acid-containing ink is not particularly limited as long as uniform film formation can be achieved, but is preferably 1 to 50% by weight, and more preferably 40 to 50% by weight.

  In order to obtain preferable piezoelectricity, in the poly α-amino acid-containing ink, the catalyst used for the synthesis of the poly α-amino acid (for example, the above-mentioned catalyst such as p-toluenesulfonic acid) can be used. It is preferable that the ink is not substantially contained in the α-amino acid-containing ink. The concentration of the residual catalyst is preferably 6.0% by weight or less, more preferably 1.0% by weight or less, further preferably 0.5% by weight or less, and particularly preferably 0.1% by weight or less.

  As another method of filling the gap between the conductor portions with an organic material exhibiting piezoelectricity or having a void, a film made of an organic material exhibiting piezoelectricity has a predetermined outer shape and a predetermined thickness. The method of forming and sticking to a conductor layer through an adhesive bond layer is mentioned.

In the membrane switch of the present invention, other members than those described above can be optionally added within the range where the effects of the present invention are exhibited. For example, an aspect in which a front film is further laminated on the outer surface of one substrate and a back film is further laminated on the outer surface of the other substrate, or a shield conductor layer that blocks noise from the outside is provided The aspect provided to the outer surface of both the board | substrates is mentioned, Between each layer, an adhesive bond layer can be interposed suitably.
Various products using the membrane switch of the present invention can be provided with a decorative layer to decorate the surface according to its use, or a sealing layer to improve durability, or an adhesive layer can be further provided. The adhesive layer may be used for assembling and the like.

  The membrane switch of the present invention can be used in combination with various sensors. For example, when combined with sensors such as temperature, acceleration, and radiation, a plurality of pieces of information can be sensed simultaneously, and information such as temperature can also be used for correcting the output of the switch of the present invention.

By applying the membrane switch of the present invention to various articles, that is, by arranging the membrane switch along the surface layer of various articles (including arrangements that appear on the surface and arrangements that do not appear on the surface), An article provided with a function of generating a signal corresponding to the applied pressure is obtained. In addition, since the above organic material is used as a material for the portion exhibiting piezoelectricity, it is possible to produce a large area at a lower cost than existing switches and sensors.
Unlike existing keyboards, mice, touch panels, microphones, etc., this can be a completely new form of human-computer interface and is expected to be used in a wide range of applications.
For example, if it is used on the surface of a robot, a signal of each part corresponding to the touch of something or the strength of the touch can be obtained, so that artificial skin can be given to the robot. If used as an alternative to a touch panel on a smartphone, tablet terminal, or PC body, the existing touch panel can only obtain the touched X and Y coordinates as a signal, but if the membrane switch of the present invention is used, the touch You can tell the computer the strength that is.

In addition, if the membrane switch is placed along the surface layer of a load-bearing part such as a bed, mat, chair (sofa, wheelchair, vehicle (including cars, railcars, aircraft, etc.) seats) Since the signal of each part according to the distribution of the load received from the person can be obtained, the in-plane distributed load can be visualized, the body pressure can be measured, and pressure ulcers can be prevented. In addition, by analyzing the numbers of the pressure sensor, it is possible to sense a pulse, respiration, and the like, and it is possible to convert physical condition and the like into data.
For the use as described above, an external device may be appropriately connected to a computer including a display device, a printer, an input device, and the like.
Below, more specific application examples are given.
Various sensors that measure the intensity distribution of biological signals such as the pulse (heartbeat), breathing, and body movement of a living body by arranging multiple sensor elements that detect minute vibrations on the support surface such as a bed, mat, chair, and seat The device is known. The membrane switch of the present invention may be used in place of one or more sensor elements arranged on a bed or the like in such a measuring apparatus. A signal obtained from the membrane switch used in place of each sensor element may be appropriately converted into a voltage and digital and processed as a biological signal. Each switch included in the membrane switch is appropriately provided with a filter for extracting a biological signal in a predetermined frequency band from the output of the membrane switch and an arithmetic unit for calculating the intensity value of the biological signal for each switch part. The intensity distribution may be generated by associating the arrangement of the portions with the intensity value.
The bed and chair as described above may be of a posture changing type (a configuration that can be folded and changed from a flat bed to a form having a backrest portion) like a sofa bed or a hospital bed. In this case, if the biological signals obtained from a plurality of switch portions arranged according to each posture are weighted, the biological signals can be extracted with higher accuracy. As described above, when the membrane switch of the present invention is used instead of the sensor element, various signal processing may be appropriately added.
Further, since the vibration signal related to the heartbeat and the pulse is very small, the heartbeat may be difficult to detect due to external vibration noise. With respect to such a problem, two or more switch portions of the membrane switch according to the present invention are arranged on a bed or the like, and a biological vibration is detected by all the switch portions. At this time, vibration noise is also detected as a vibration element by each switch portion. However, the biological vibrations of breathing, heartbeat, and body movement are the same timing for all sensor elements, so by looking at the timing of breathing, heartbeat, and body movement that is common information from each sensor element, Vibration noise can be effectively eliminated by calculation.
As described above, by using the present invention instead of the pressure sensor, an apparatus capable of preferably measuring the intensity distribution of the biological signal distributed on the support surface such as a bed, mat, or sheet can be obtained.

In addition, a foot pressure measurement sheet (a sheet that measures how much load is transferred to the ground by which area of the sole of the foot), and a tooth meshing measuring instrument (by pinching between the upper and lower teeth, and which bite A sheet-like pressure measuring device is constructed by constructing an article using the sheet-like form of the membrane switch as it is, such as a sheet for measuring how much compression load is applied to the object by the teeth. It becomes possible.
In either case, the membrane switch is used so as to function as a sheet-like pressure-sensitive head, and can be configured to measure changes in current and capacitance between each conductor using an external measuring device. That's fine.
Furthermore, the membrane switch of the present invention can be used as a substitute for a piezoelectric element in various sensors known to use a piezoelectric element such as a piezoelectric acceleration sensor and a gyro sensor.
Furthermore, by arranging the membrane switch of the present invention along the surface layer of various articles (including the arrangement that appears on the surface and the arrangement that does not appear on the surface), the voltage generated according to the pressure applied from the outside is utilized. Articles such as a power generation device and an energy harvesting device (a device that collects minute energy into electric power or the like) are also obtained.
Furthermore, the membrane switch according to the present invention is arranged along the surface layer of various articles (including the arrangement that appears on the surface and the arrangement that does not appear on the surface), thereby driving generated in response to an electrical signal such as an externally applied voltage. Articles such as actuators utilizing force and the like are also obtained.
The membrane switch of the present invention is expected to have applications that could not be considered by extension of conventional membrane switches such as energy harvesting. If the charge generated by the membrane switch of the present invention is passed through a rectifier circuit and then stored in a capacitor or the like, the energy can be used. The stored electrical energy can be used as a power source for driving various circuits connected to the membrane switch, and a self-power generation sensor that does not require an external power source and a battery can be configured. It can also be used as a power source for various sensors used in combination with the membrane switch.

  The present invention will be described more specifically with reference to the following experimental examples, but the scope of the present invention is not limited to the following experimental examples.

  EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated in detail, this invention is not limited by the Example described below.

[Synthesis of poly α-amino acid]
Synthesis Example 1: Synthesis of γ-methyl-L-glutamic acid / γ-hexyl-L-glutamic acid copolymer (Step 1) Synthesis of poly-γ-methyl-L-glutamic acid 410 ml of 1,2-dichloroethane (manufactured by Kanto Chemical Co., Inc.) ), N-carboxy-γ-methyl-L-glutamic anhydride (54.92 g, 293.45 mmol) was added, cooled to 0 ° C., and N, N-dimethyl-1,3-propanediamine as an initiator (366 μl, 2.93 mmol, manufactured by Kanto Chemical Co., Inc.) was added, and the mixture was stirred at 25 ° C. for 1 day to obtain poly-γ-methyl-L-glutamic acid. The weight average molecular weight Mw was measured by the following method (measurement method 1). The weight average molecular weight Mw was 1.9 × 10 ⁴ .
(Step 2) Side chain substitution reaction (transesterification reaction) of poly-γ-methyl-L-glutamic acid
9.3 g of the poly-γ-methyl-L-glutamic acid prepared above was dissolved in 45 ml of 1,2-dichloroethane, and 1-hexanol (16 ml, 130.00 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) and p-toluenesulfonic acid 1 Hydrate (1.24 g, 6.50 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) was added, and the mixture was stirred at 80 ° C. for 1 day to conduct a transesterification reaction. Γ-methyl-L-glutamic acid / γ-hexyl-L-glutamic acid A copolymer was obtained. About the obtained copolymer, the weight average molecular weight Mw of the copolymer was measured by the following method (measurement method 1). Further, the composition of the polymer after the transesterification reaction was measured by the following method (Measurement Method 2).

Synthesis Examples 2-3, 5-6, 8-13: Synthesis of various poly α-amino acids After obtaining poly-γ-methyl-L-glutamic acid by the same method as in Synthesis Example 1, it was converted to 1,2-dichloroethane. Dissolve and add an appropriate amount of the alcohol shown in Table 1 (introduction alcohol column) to the glutamic acid unit of poly-γ-methyl-L-glutamic acid, add a catalytic amount of p-toluenesulfonic acid monohydrate, Various poly α-amino acids (copolymers) were obtained by the procedure of stirring for 5 days. About the obtained copolymer, the weight average molecular weight Mw of the copolymer was measured by the following method (measurement method 1). Further, the composition of the polymer after the transesterification reaction was measured by the following method (Measurement Method 2).

Synthesis Example 4: Synthesis of γ-benzyl-L-glutamic acid / γ-dodecyl-L-glutamic acid copolymer (Step 1) Synthesis of poly-γ-benzyl-L-glutamic acid 265 ml of 1,2-dichloroethane (manufactured by Kanto Chemical Co., Inc.) ) With N-carboxy-γ-benzyl-L-glutamic anhydride (44.2 g, 167.98 mmol) and N, N-dimethyl-1,3-propanediamine (208.2 μl, 1.68 mmol) as an initiator. In addition, the mixture was stirred at 25 ° C. for 3 days to obtain poly-γ-benzyl-L-glutamic acid. The weight average molecular weight Mw was measured by the following method (measurement method 1). The weight average molecular weight Mw was 2.2 × 10 ⁴ .
(Step 2) Side chain substitution reaction (transesterification reaction) of poly-γ-benzyl-L-glutamic acid
Poly-γ-benzyl-L-glutamic acid (10 g, 45.6 mmol) prepared above was dissolved in 170 ml of 1,2-dichloroethane, 1-dodecanol (10.2 ml, 45.6 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) and p-Toluenesulfonic acid monohydrate (2.6 g, 13.68 mmol) was added, and the mixture was stirred at 65 ° C. for 1 day to obtain a γ-benzyl-L-glutamic acid / γ-dodecyl-L-glutamic acid copolymer. It was. About the obtained copolymer, the weight average molecular weight Mw of the copolymer was measured by the following method (measurement method 1). Further, the composition of the polymer after the transesterification reaction was measured by the following method (Measurement Method 2).

Synthesis Example 7: Synthesis of γ-benzyl-L-glutamic acid / γ-2-norbornylmethyl-L-glutamic acid copolymer After obtaining poly-γ-benzyl-L-glutamic acid by the same method as in Synthesis Example 4, It is dissolved in 1,2-dichloroethane, and an equivalent amount of norbornane-2-methanol (manufactured by Tokyo Chemical Industry Co., Ltd.) and a catalytic amount of p-toluenesulfonic acid per water with respect to the glutamic acid unit of poly-γ-benzyl-L-glutamic acid. The hydrate was added and stirred at 65 ° C. for 4 days to obtain a γ-benzyl-L-glutamic acid / γ-2-norbornylmethyl-L-glutamic acid copolymer. About the obtained copolymer, the weight average molecular weight Mw of the copolymer was measured by the following method (measurement method 1). Further, the composition of the polymer after the transesterification reaction was measured by the following method (Measurement Method 2).

Synthesis Example 14: Synthesis of γ-methyl-L-glutamic acid / N ^ε -benzyloxycarbonyl-L-lysine copolymer N ^α -carboxy-N ^ε -benzyloxycarbonyl-L-lysine anhydrous in 130 ml of 1,2-dichloroethane Product (4.02 g, 13.12 mmol) and N-carboxy-γ-methyl-L-glutamic anhydride (2.46 g, 13.12 mmol) were added, and N, N-dimethyl-1,3-propane was used as an initiator. Diamine (32.78 μl, 0.262 mmol) was added and stirred at 25 ° C. for 1 day to obtain a γ-methyl-L-glutamic acid / N ^ε -benzyloxycarbonyl-L-lysine copolymer. The weight average molecular weight Mw of the copolymer was measured by the following method (Measurement Method 1). Moreover, the composition of the copolymer was measured by the following method (measurement method 2).

Synthesis Examples 15 to 18: Synthesis of various copolymers In the same manner as in Synthesis Example 14, 1,2-dichloroethane was equimolar with two N-carboxy-L-amino acid anhydrides (component A and component B) shown in Table 2. 1/100 equivalent amount of N, N-dimethyl-1,3-propanediamine as an initiator was added to the amino acid anhydride and stirred for 2 to 3 days to obtain various polyamino acid copolymers. The weight average molecular weight Mw of the copolymer was measured by the following method (Measurement Method 1). Moreover, the composition of the copolymer was measured by the following method (measurement method 2).

Synthesis Example 19: [gamma] -methyl-L-glutamic acid (68%)-N [ ^epsilon] -benzyloxycarbonyl-L-lysine block (32%) copolymer synthesis N-carboxy- [gamma] -methyl- in 20 ml of 1,2-dichloroethane After adding L-glutamic anhydride (5.00 g, 26.72 mmol), the mixture was cooled to 0 ° C., and N, N-dimethyl-1,3-propanediamine (66.80 μl, 0.534 mmol) was used as an initiator. In addition, after stirring at 25 ° C. for 1 day, the mixture was cooled again to 0 ° C., 20 ml of 1,2-dichloroethane was added, and then N ^α -carboxy-N ^ε -benzyloxycarbonyl-L-lysine anhydride (4 0.09 g, 13.36 mmol) was added, and the mixture was stirred at 25 ° C. for 1 day, and γ-methyl-L-glutamic acid-N ^ε -benzyloxycarbonyl-L-lysate was added. A gin block copolymer was obtained. The weight average molecular weight Mw of the copolymer was measured by the following method (Measurement Method 1). Moreover, the composition of the copolymer was measured by the following method (measurement method 2).

Synthesis Example 20: Synthesis of γ-methyl-L-glutamic acid (41%)-N ^ε -benzyloxycarbonyl-L-lysine (18%)-γ-methyl-L-glutamic acid (41%) block copolymer Synthesis Example After obtaining γ-methyl-L-glutamic acid-N ^ε -benzyloxycarbonyl-L-lysine block copolymer in the same manner as in No. 19, the mixture was cooled again to 0 ° C. and 10 ml of 1,2-dichloroethane was added. , N-carboxy-γ-methyl-L-glutamic anhydride (5.00 g, 26.72 mmol) was added and stirred at 25 ° C. for 2 days, and γ-methyl-L-glutamic acid-N ^ε -benzyloxy was added. A carbonyl-L-lysine-γ-methyl-L-glutamic acid block copolymer was obtained. The weight average molecular weight Mw of the copolymer was measured by the following method (Measurement Method 1). Moreover, the composition of the copolymer was measured by the following method (measurement method 2).

Synthesis Example 21 Synthesis of γ-benzyl-L-glutamic acid (50%)-N ^ε -benzyloxycarbonyl-L-lysine (50%) block copolymer (low molecular weight) N-to 10 ml of 1,2-dichloroethane Carboxy-γ-benzyl-L-glutamic anhydride (1.00 g, 3.80 mmol) was added, and then cooled to 0 ° C., and N, N-dimethyl-1,3-propanediamine (9.56 μl) was used as an initiator. 0.076 mmol) and stirred at 25 ° C. for 1 day, and then cooled again to 0 ° C., and N ^α -carboxy-N ^ε -benzyloxycarbonyl-L-lysine anhydride (1.16 g, 3. 80 mmol), and stirred at 25 ° C. for 1 day. A γ-benzyl-L-glutamic acid-N ^ε -benzyloxycarbonyl-L-lysine block copolymer (low content) A dimer). The weight average molecular weight Mw of the copolymer was measured by the following method (Measurement Method 1). Moreover, the composition of the copolymer was measured by the following method (measurement method 2).

Synthesis Example 22 Synthesis of γ-benzyl-L-glutamic acid (53%)-N ^ε -benzyloxycarbonyl-L-lysine (47%) block copolymer (high molecular weight) N-to 10 ml of 1,2-dichloroethane Carboxy-γ-benzyl-L-glutamic anhydride (1.00 g, 3.80 mmol) was added, and then cooled to 0 ° C., and N, N-dimethyl-1,3-propanediamine (0.48 μl) was used as an initiator. 3.8 μmol) was added, and the mixture was stirred at 25 ° C. for 1 day, then cooled again to 0 ° C., and N ^α -carboxy-N ^ε -benzyloxycarbonyl-L-lysine anhydride (1.16 g, 3. 80 mmol) was added and the resulting mixture was being stirred 3 days at 25 ° C., .gamma.-benzyl -L- glutamic acid -N ^epsilon - benzyloxycarbonyl -L- lysine block copolymer (high molecular weight ) Was obtained. The weight average molecular weight Mw of the copolymer was measured by the following method (Measurement Method 1). Moreover, the composition of the copolymer was measured by the following method (measurement method 2).

[Measurement of physical properties of polyamino acids]
Measuring method 1: Measuring method of weight average molecular weight The weight average molecular weight Mw was measured using gel permeation chromatography (GPC). Specifically, an analytical column device (Showa Denko, Shodex K-802 and K-806M) is attached to a GPC analyzer (Hitachi, LaChrom Elite), and 10 to 80 μl of a separately prepared measurement solution is injected. The eluent flow rate was 1 ml / min, and the column holding temperature was 40 ° C. The measurement solution was prepared by dissolving in chloroform so that the polyamino acid concentration would be 0.25 to 3.0% (w / v), followed by filter filtration. The weight average molecular weight Mw was calculated by comparing the retention time of the obtained peak with the retention time of a separately measured polystyrene for calibration (Shodex STANDARD SM-105, manufactured by Showa Denko KK).

Measurement method 2: Composition measurement method of copolymer after transesterification reaction After dissolving 10 mg of sample in deuterated chloroform or deuterated trifluoroacetic acid, ¹ H nuclear magnetic resonance spectrum ( ¹ HNMR, BRUKER, 400 MHz) was analyzed. The composition was calculated by comparing the peak areas of protons at the α-position of the amino acid before and after transesterification or during copolymerization. A measurement example is shown below.

Composition measurement of γ-methyl-L-glutamic acid / γ-hexyl-L-glutamic acid copolymer 10 mg of the synthesized copolymer was dissolved in deuterated trifluoroacetic acid, and ¹ HNMR was measured. A peak derived from the methyl group of methyl-L-glutamic acid was detected, and a peak derived from the α-position proton of γ-methyl-L-glutamic acid and γ-hexyl-L-glutamic acid was detected in the vicinity of 4.7 ppm. When the peak area near 3.8 ppm is A and the peak area near 4.7 ppm is B, A / B = 1.17. In the case of poly-γ-methyl-L-glutamic acid, since A / B = 3.00, it is considered that the hexyl group is substituted by a reduced amount. Therefore, the content of hexyl groups is from 1.83 / 3.00 = 0.61 to 61%. Therefore, the composition of the copolymer is γ-methyl-L-glutamic acid (39%) / γ-hexyl-L-glutamic acid (61%).

Composition measurement of γ-benzyl-L-glutamic acid / N ^ε -benzyloxycarbonyl-L-lysine copolymer 10 mg of the synthesized copolymer was dissolved in deuterated trifluoroacetic acid and ¹ HNMR was measured to be around 5.1 ppm The peaks derived from the benzyl group of N ^ε -benzyloxycarbonyl-L-lysine and the benzyl group of γ-benzyl-L-glutamic acid, and γ-benzyl-L-glutamic acid around 4.7 ppm and N ^ε near 4.4 ppm A peak derived from the α-position proton of -benzyloxycarbonyl-L-lysine was detected. Assuming that peak areas near 5.1 ppm, 4.7 ppm, and 4.4 ppm are A, B, and C, respectively, A / B = 4.00, A / C = 4.00, and B / C = 1.00. . Since both B and C represent the area of one proton, the composition of the copolymer is γ-benzyl-L-glutamic acid (50%) / N ^ε -benzyloxycarbonyl-L-lysine (50%). Become.

  As shown in the above two examples, when γ-methyl-L-glutamic acid is included, the peak area at the methyl group and α-position, and when γ-benzyl-L-glutamic acid is included, the peak area at the benzyl group and α-position By comparing, the composition of the copolymer after the transesterification reaction can be calculated.

Evaluation Method 3: Measurement of Piezoelectricity The piezoelectric properties of the poly α-amino acids of Synthesis Examples 1, 3, 4, 6, 7, 15, 19, 20, 21, and 22 were confirmed.
On a polyethylene terephthalate (PET) substrate (thickness: 125 ± 5 μm, length: 18 mm, width: 12 mm) on which ITO (indium tin oxide) is deposited as an electrode, a suitable solvent from a poly α-amino acid solution is used as a piezoelectric film. A polymer thin film was prepared by casting. An element is manufactured by sandwiching this thin film with a PET substrate on which an ITO electrode is deposited, and an electromotive force generated when a load (about 6 kg) is applied to the manufactured element is measured at room temperature using a source meter manufactured by KEITHLEY. (20 ° C).

  Poly-γ-methyl-L-glutamic acid (Mw: 3.3 × 104) and poly-γ-benzyl-L-glutamic acid (Mw: 3.8 × 104) used were commercially available from Sigma-Aldrich. Is available.

  Table 4 shows that the polyamino acid of the present application has piezoelectricity.

[Formulation Example 1: Preparation of polyamino acid ink]
The γ-benzyl-L-glutamic acid (50%)-Nε-benzyloxycarbonyl-L-lysine (50%) block copolymer prepared in Synthesis Example 21 was added to an excess amount of ether for reprecipitation, followed by precipitation. Was dried overnight with a vacuum pump. 36 parts by weight of solid of the obtained γ-benzyl-L-glutamic acid (50%)-Nε-benzyloxycarbonyl-L-lysine (50%) block copolymer, 4 parts by weight of silica particles, 30 parts by weight of carbitol acetate Then, 30 parts by weight of γ-butyllactone was stirred for about 5 to 30 minutes using Awatori Nertaro ARE-310 (manufactured by Sinky Corporation) until uniform. A polyamino acid ink was prepared by mixing this with three rolls.

Details of the components used are as follows.
Silica particles: Nippon Aerosil Co., Ltd., trade name “RY-200”, particle diameter specific surface area: 100 m ² / g
Carbitol acetate (EDGAc): manufactured by Kanto Chemical Co., Inc. γ-Butyllactone (GBL): Pure Chemical

[Production Example 1: Fabrication of membrane switch]
A membrane switch shown in FIG. 1A was produced based on the following production method.
A square polyimide film with a thickness of 50 μm and a side of 100 mm (“Kapton (registered trademark) 200H” manufactured by Toray DuPont Co., Ltd.) was used as a substrate, and a conductive silver paste (manufactured by Toyochem Co., Ltd.) in the center on the surface of the substrate. “RA FS 059”) was used to form one square (25 mm per side) conductor part and a wiring circuit having a width of 500 μm connected to the conductor part. More specifically, the conductive silver paste is deposited on the polyimide film using a screen printing method so as to draw a conductor and a wiring circuit, dried at 150 ° C. for 5 minutes, and then baked at 250 ° C. for 5 minutes. To obtain a conductor layer. The measured value of the thickness of each of the conductor part and the wiring circuit after firing was 8 μm.
In order to make two said board | substrates oppose, two sheets of the same structure were produced about one sample. In this example, since the conductor part and the wiring circuit have a simple shape, the configurations of the two boards are the same, but on one board (conductor part, wiring circuit) and on the other board (Conductor portion, wiring circuit) are in a mirror-image-corresponding relationship with each other so as to coincide with each other.
A polyimide tape with an adhesive layer (Toray DuPont Co., Ltd.) on one of the two substrates so as to be parallel to the four sides of the conductor portion and to cover the outer peripheral edge portion of the conductor portion with a width of 1 mm over the entire circumference. 4 sheets of “Kapton tape” (100 μm thick) were pasted to surround the conductor portion and serve as a spacer. This is a prototype forming method assuming a case where a spacer is formed and attached as a separate member, and is a case where a through hole is punched out by a press.
While the outer shape of the conductor portion is a square with a side of 25 mm, the opening shape of the central through hole formed by being surrounded by four polyimide tapes is a square with a side of 23 mm.
200 μL of the polyamino acid solution (solvent: 1,2-dichloroethane, solution concentration 12.8% (w / w)) synthesized in Synthesis Example 21 was dropped into the through hole of the spacer of the substrate as it was, The inside of the through hole was filled with the solution and dried at room temperature for 1 day to remove the solvent, thereby forming a layer of organic material exhibiting piezoelectricity.
On the substrate on which the spacer and the organic material exhibiting piezoelectricity are formed, the other substrate prepared first is overlapped so that the conductor portion is below, and the outer peripheral edge of the substrate is fixed with a double-sided adhesive tape. A membrane switch was obtained.
For testing purposes, a total of four samples having the same configuration were produced by the above-described manufacturing procedure.

  In the case of the polyamino acid solutions of Synthesis Examples 1, 3, 4, 6, 7, 15, 19, 20, and 22, as in Production Example 1, the solutions shown in Table 5 were filled in the through holes, respectively. An inventive membrane switch is obtained.

[Production Example 2: Fabrication of membrane switch]
(Process common to upper substrate (first substrate) and lower substrate (second substrate))
Conductor part (1 side 25mm) by subtractive method using dry film resist ("ALHO NIT4015" manufactured by Nichigo Morton Co., Ltd.) on polyimide with copper foil ("FELIOS film 25μm-copper foil 9μm" manufactured by Panasonic Corporation) And a wiring pattern was formed.
Using dry film resist ("ALPHON NIT4015" manufactured by Nichigo-Morton Co., Ltd.), cover the surface of the conductor part except the surface of the conductor part and the end part of the wiring part (the place where it will finally become the connector part) as the resist for plating. And the electroless Ni plating (thickness 3 μm) was applied to the end of the wiring part, and further the electric field Au plating (thickness 0.03 μm) was applied thereon to obtain a conductor part and wiring part having a two-layer structure.
After peeling off the dry film, a spacer was created by printing a solder resist ink for flexible substrates (“AE-70-M11” manufactured by Ajinomoto Fine Techno Co., Ltd.). The material was arranged so that it was 20 μm from the upper surface and 8 μm from the upper surface of the Au layer).
Further, as in the case of Preparation Example 1, the outer shape of the conductor portion was a square with a side of 25 mm, whereas the opening shape of the central through hole formed surrounded by the resist ink had a side of 23 mm. It was a square. That is, the resist ink covers the outer peripheral edge of the conductor portion by a width of 1 mm over the entire circumference.
The resist ink was heated at 100 ° C. for 30 minutes to volatilize the solvent to a semi-cured state.
(Process for the lower substrate (second substrate) only)
The polyamino acid ink prepared in Formulation Example 1 was formed by screen printing so that the final thickness after curing was 10 μm in the opening formed with the semi-cured resist ink. This was heated at 150 ° C. for 30 minutes to volatilize the solvent of the polyamino acid ink and simultaneously perform the main curing of the resist ink.
(Lamination of the first and second substrates)
Obtained by the first substrate obtained in the above (process common to the upper substrate (first substrate) and the lower substrate (second substrate)) and the above (step of only the lower substrate (second substrate)). The obtained 2nd board | substrate was bonded together with the hot roll laminator.
Then, ACF was interposed in the part which should make each wiring of both boards conductive, and it bonded together using the iron, and made both wirings conduct. By heating this at 150 ° C. for 30 minutes, the resist ink of the first substrate, which was semi-cured, ACF was fully cured.

Evaluation Method 1: Evaluation of Signal Obtained by Applying Load to Membrane Switch Obtained in Preparation Example 1 using a desktop precision universal testing machine (“AGS-X Series” manufactured by Shimadzu Corporation, load cell 10N used) For each of the four membrane switch samples, a load was applied to the center of the conductor via a disk with a diameter of 20 mm, and the value of the capacitance between the conductors that changed as the load increased was measured. did.
In the capacitance measurement, an LCR meter (“4284A Precision LCR Meter” manufactured by Agilent Technologies, Inc.) is used, and the load is changed between a load of 0.5 to 7.5 N at a measurement frequency of 30 Hz. Capacitance was measured.
When the slope of the electrostatic capacitance with respect to the load applied to the membrane switch of [Preparation Example 1] was calculated by the method of least squares, it was 0.55 pF / N, and the average of the correlation coefficient was 0.98. As a result, it was found that if a change in capacitance is taken out as an electric signal, a signal having a strong correlation with the force acting on the membrane switch can be obtained.

Unlike the conventional membrane switch, the membrane switch of the present invention can obtain a signal corresponding to the pressure, so that a new function can be given to a keyboard, a switch, and the like.
In addition, because it is possible to supply a large-area pressure measurement board at a very low cost, body pressure and foot pressure distribution measurements, dental pressure sensors, human seat sensors, breathing and pulse scanners, games Unlike conventional membrane switches, such as machine and smartphone interfaces and toy sensors, it is expected to be used in a wide range of fields from consumer to industrial use in medical, nursing and healthcare.
In addition, new applications such as energy harvesting that are not an extension of conventional membrane switches are also expected.

DESCRIPTION OF SYMBOLS 1 1st board | substrate 1a 1st conductor part 2 2nd board | substrate 2a 2nd conductor part 3 Spacer 3a Through-hole 4 Organic material which shows piezoelectricity

Claims (30)

A first conductor portion is provided on the first substrate, a second conductor portion is provided on the second substrate, and the conductor portions are opposed to each other with a gap therebetween. Having a structure in which the second substrate is laminated via a spacer;
The gap is filled with an organic material exhibiting piezoelectricity, or
In the gap, an organic material exhibiting piezoelectricity is disposed such that a gap exists between the organic material and one conductor portion.
Membrane switch. A plurality of first conductor portions are provided in a predetermined arrangement pattern on the first substrate, and a plurality of second conductor portions are provided in an arrangement pattern corresponding to the arrangement pattern on the second substrate,
The first substrate and the second substrate are laminated via a spacer so that the plurality of conductor portions face each other with a gap and a plurality of conductor portion pairs are arranged, The membrane switch according to claim 1, wherein a gap between the conductor portions of the conductor portion pair is filled with an organic material exhibiting piezoelectricity or disposed so that a gap exists.   The membrane switch according to claim 1 or 2, wherein a gap between the conductor portions is surrounded by a spacer.   The membrane switch according to any one of claims 1 to 3, wherein the spacer is formed by punching a film having a thickness of the spacer and made of a material of the spacer.   The spacer according to any one of claims 1 to 3, wherein the spacer is formed by applying an insulating material to one or both of the main surface of the first substrate and the main surface of the second substrate. The membrane switch according to one item.   The membrane switch according to claim 5, wherein the material of one or both of the first substrate and the second substrate and the material of the spacer are the same insulating material. An organic material that exhibits piezoelectricity
(A) an organic piezoelectric body having piezoelectricity itself,
(B) By using an organic piezoelectric body having piezoelectricity as a base material, and fillers made of other materials having the piezoelectricity itself dispersed therein, the piezoelectricity of the base material itself is different as a whole. Composite materials that are organic materials that exhibit piezoelectricity, or
(C) An organic material having no piezoelectricity is used as a base material, and a filler made of a material having piezoelectricity is dispersed therein, so that it is selected from composite materials that are organic materials that exhibit piezoelectricity as a whole. The membrane switch according to any one of claims 1 to 6, wherein the membrane switch is one or more types.   The membrane switch according to any one of claims 1 to 6, wherein the organic material exhibiting piezoelectricity is a polyamino acid.   Polyamino acids from glycine, alanine, valine, leucine, isoleucine, arginine, asparagine, aspartic acid, cystine, cysteine, glutamine, glutamic acid, histidine, lysine, ornithine, serine, threonine, tryptophan, methionine, phenylalanine, tyrosine and their derivatives The membrane switch according to claim 8, which is a poly α-amino acid containing one or two or more selected units. Polyamino acids
A unit represented by the following formula (I):
A unit represented by the following formula (II):
A unit represented by the following formula (III):
The poly α-amino acid containing a unit represented by the following formula (IV) and one or more units selected from the unit represented by the following formula (V): Membrane switch.
Formula (I):

(In the formula, k represents an integer of 1 or 2, R ¹ represents a C _{1 to} C ₈ substituted or unsubstituted alkyl group, or a benzyl group which may be substituted with a halogen atom, an alkoxy group or a nitro group. .)
Formula (II):

(Wherein, k is an integer of 1 or 2, R ² is a C _{3 to} C ₁₆ unsubstituted alkyl group, or a part or all of hydrogen atoms are halogen atoms, C _{3 to} C ₁₂ alicyclic hydrocarbon groups, A C ₁ -C ₆ alkoxy group, a cyano group, an optionally substituted phenyl group, an optionally substituted phenylalkoxy group or an optionally substituted phenylalkylcarbamate group Represents a substituted C ₁ -C ₆ alkyl group, provided that R ² is not the same group as R ^{1 in} formula (I).
Formula (III):

(Wherein R ³ is a methyl group, a benzyl group, or — (CH ₂ ) ₄ —NHX group (where X is a benzyloxycarbonyl group optionally substituted with a halogen atom or a C ₁ -C ₆ alkoxy group, a halogen atom) substituted C ₁ optionally -C ₆ alkylcarbonyl group atom, allyloxycarbonyl group, fluorenyl alkoxycarbonyl group, C ₁ -C ₆ alkyl group or a benzene sulfonyl group which may be substituted with a nitro group or, represents a C ₁ -C ₆ alkyloxycarbonyl group.) represents a.)
Formula (IV):

(In the formula, k is an integer of 1 or 2, R ⁴ is a C _{1 to} C ₁₂ alkoxy group, a C _{1 to} C ₁₂ alkyl group in which part or all of the hydrogen atoms are substituted with halogen atoms, or C ₁ to It represents C ₁₂ alkylcarbonyl group, m-number of ^{R 4} is selected from the same or different .l 6 to 12 integer, m is an integer of 1-3.)
Formula (V):

(In the formula, R ⁵ represents a hydrogen atom, a methyl group, —CH (OH) CH _{3, a} C _{3 to} C ₄ branched alkyl group, or — (CH ₂ ) _n —Z (where n is 1 to An integer of 4, Z is a hydroxy group, a mercapto group, a carboxy group, a methylsulfanyl group, an amino group, a substituted aryl group, an aminocarbonyl group, —NH—C (NH ₂ ) ═NH,

Or

Represents. ). ) Poly alpha-amino acid is
(A) one or more units represented by formula (I);
(B) a poly α-amino acid containing a unit represented by formula (II), a unit represented by formula (III), and one or more units selected from units represented by formula (IV) The membrane switch according to claim 10. The R ² is a C _{6 to} C ₁₆ unsubstituted alkyl group, or a C _{1 to} C ₆ substituted alkyl group in which part or all of the hydrogen atoms are substituted with a fluorine atom or a norbornyl group. Membrane switch. The membrane switch according to claim 10 or 11, wherein R ² is an n-hexyl group, an n-dodecyl group, a 2-norbornylmethyl group, or a 2,2,2-trifluoroethyl group. R ³ is a methyl group or _{- (CH} 2) 4 -NHX group (, X represents a benzyloxycarbonyl group), a membrane switch of any one of claims 10 to 13. R ⁴ is a C _{1 to} C ₆ alkoxy group, a C _{1 to} C ₁₂ alkyl group in which a part or all of hydrogen atoms are substituted with a fluorine atom, or a C _{3 to} C ₉ alkyl carbonyl group. The membrane switch according to any one of 14. The membrane switch according to any one of claims 10 to 14, wherein R ⁴ is a methoxy group, a butoxy group, a hexyloxy group, a trifluoromethyl group, or an n-hexylcarbonyl group. The R ⁵ is a hydrogen atom, a 4-aminobutyl group, a 4-hydroxybenzyl group, an aminocarbonylethyl group, or — (CH ₂ ) ₃ —NH—C (NH ₂ ) ═NH. A membrane switch according to claim 1.   The membrane switch according to claim 10, wherein the polyamino acid is a poly α-amino acid containing one or more units selected from glutamic acid, aspartic acid, lysine and derivatives thereof.   The polyamino acid is a polyα-amino acid containing one or more units selected from glutamic acid methyl ester, glutamic acid benzyl ester, aspartic acid benzyl ester, Nε-carbobenzoxy-L-lysine. 10. The membrane switch according to 10. The poly α-amino acid is γ-methyl-L-glutamic acid / γ-hexyl-L-glutamic acid copolymer, γ-methyl-L-glutamic acid / γ-dodecyl-L-glutamic acid copolymer, γ-benzyl-L- Glutamic acid / γ-dodecyl-L-glutamic acid copolymer, γ-methyl-L-glutamic acid / γ-2,2,2-trifluoroethyl-L-glutamic acid copolymer, γ-methyl-L-glutamic acid / γ- 2-norbornylmethyl-L-glutamic acid copolymer, γ-benzyl-L-glutamic acid / γ-2-norbornylmethyl-L-glutamic acid copolymer, γ-methyl-L-glutamic acid / γ- (6 -(P-methoxyphenoxy) -1-hexyl) -L-glutamic acid copolymer, γ-methyl-L-glutamic acid / γ- (6- (p-hexylcarbonylphenoxy) ) -1-hexyl) -L-glutamic acid copolymer, γ-methyl-L-glutamic acid / γ- (10- (p-methoxyphenoxy) -1-decyl) -L-glutamic acid copolymer, γ-methyl- L-glutamic acid / γ- (6- (p-butoxyphenoxy) -1-hexyl) -L-glutamic acid copolymer, γ-methyl-L-glutamic acid / γ- (6- (p-hexyloxyphenoxy) -1 -Hexyl) -L-glutamic acid copolymer, γ-methyl-L-glutamic acid / γ- (6- (3,5-bis (trifluoromethyl) phenoxy) -1-hexyl) -L-glutamic acid copolymer, γ-methyl-L-glutamic acid / N ^ε -benzyloxycarbonyl-L-lysine copolymer, γ-benzyl-L-glutamic acid / N ^ε -benzyloxycarbonyl-L-lysine copolymer Polymer, γ-methyl-L-glutamic acid / L-phenylalanine copolymer, γ-benzyl-L-glutamic acid / L-phenylalanine copolymer, and γ-benzyl-L-glutamic acid / L-alanine copolymer The membrane switch according to claim 10, wherein the membrane switch is one or more types.   The membrane switch according to any one of claims 11 to 20, wherein the poly α-amino acid is a random copolymer.   The membrane switch according to any one of claims 11 to 20, wherein the poly α-amino acid is a block copolymer.   The membrane switch according to any one of claims 10 to 22, wherein the poly α-amino acid has a weight average molecular weight (Mw) of 1,000 to 5,000,000.   24. Any one of claims 1 to 23, wherein an organic material arranged so that a gap or a gap exists in a gap between conductor portions is subjected to a polarization treatment by applying a voltage between the conductor portions. A membrane switch according to claim 1.   The membrane switch according to any one of claims 1 to 24, wherein either one or both of the first substrate and the second substrate is a flexible substrate formed of a flexible material.   The first substrate, the second substrate, and the spacer are formed of a flexible material, and the entire membrane switch has flexibility. The membrane switch according to one item.   25. The adhesive layer according to any one of claims 1 to 24, wherein an adhesive layer is interposed between one or both of the first substrate and the spacer and between the second substrate and the spacer. The described membrane switch.   28. The adhesive layer according to any one of claims 1 to 27, wherein an adhesive layer is interposed between the organic material disposed so that there is a filling or void in the gap between the conductor portions and the conductor portion. The membrane switch described in the section.   The first conductor portion, the second conductor portion, and the wiring circuit connected to the conductor portions are formed by printing on the first and second substrate surfaces. A membrane switch according to claim 1.   30. The article, wherein the membrane switch according to any one of claims 1 to 29 is disposed along a surface layer of an article subjected to pressure, and thereby has a function of generating a signal corresponding to the received pressure.

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